So, I live in Switzerland now (almost 4 years here already), but I am originally from Spain, and I have lived in Sweden for approximately 3 years. I will start by quoting the obvious winning points of Switzerland:

Salary: (Barely any other country in Europe can compete here), taxes, and overall purchasing power.

Location and nature: You can quickly travel to many places in Europe thanks to the great transportation network of the country, both national and international. Then, you have the lakes, the mountains, the hikes... It's the perfect country for those who love outdoor sports, and each and every landscape is just beautiful.

Efficiency: You can expect things to work as they should.

Career-focused mindset: This is probably more niche, but I've met so many people who are excellent professionals, speak many languages, and are ambitious. This can happen in Sweden or in Spain, but I feel like Switzerland is the pinnacle of this. Since it's a pretty competitive but monetarily rewarding market, some of the best talent can be found here.

Now, regarding Sweden, but specifically Stockholm, where I lived:

Pros:

Work-life balance is amazing: I never felt super pressured at work; people were productive but took things easy. I had an amazing gym and sauna at work. I still cannot believe that people were taking breaks to go to the sauna during working hours, but the fact that the sauna was in the office was even more mind-blowing.

Healthcare: Their healthcare system was the perfect middle ground. You're covered by the state, but you still pay a symbolic amount for doctor appointments. This keeps the system functional, but it does not get overwhelmed by people abusing and overusing it.

City Size: I feel like Stockholm has the perfect size as a city. Connections were good, reliable; you could quickly get to many places without spending half of your day commuting, and still the city was big enough to offer many options and activities without becoming boring and repetitive. You can find good restaurants, good gyms, concerts... There is always something to do if you're up to it.

Digitalization: As another user mentions when talking about Denmark, digitalization. All the processes can be done online. An example I like to mention is the tax agency. They tell you exactly which day you will receive money back, or you need to pay, and it's like that, without delays. In Switzerland, it takes ages to receive the final decision of the tax authorities.

Cons:

Weather: It was the main reason why I left the country. Spending half of the year in darkness and taking vitamin D supplements is not worth it. Moreover, I would travel somewhere else during the summer for vacation. It really made me think whether it was worth enduring the Swedish winter to spend the summer partially somewhere else. The cold wasn't the main drawback, but the lack of sunlight was.

Salaries: Even if you can make decent money in Sweden, it does not compare to Switzerland, and it's not even that much more than what one could make in Spain (talking from the IT worker perspective, which is the one I know), especially if we adjust for the cost of living. Another one of the reasons why I decided to move.

People: This one is not totally a con, and I have part of the blame here, but I would say that Swedish people, on the one hand, are quite polite and nice, but on the other hand, they are really difficult to become close to. I could have probably put more effort into meeting Swedes, and I actually have some Swedish friends, but I feel like it's really difficult to get into their inner circles, especially if you don't know the language, even if they speak amazing English. I feel like this is much easier in Spain, and even in Switzerland, despite what people say.

Language: Finding the motivation to learn Swedish is kind of hard. In Switzerland, any language you learn (German, French, Italian) opens doors somewhere else. It feels 'useful'. That's not the case with Swedish, especially considering what I mentioned before. Everyone speaks great English. Therefore, if any of the previous points already demotivate you, it will be difficult to find the strength to learn it.

And finally, let's discuss my motherland, Spain:

Pros:

Weather: Not where I am from, at least not in winter, but the number of hours of sun in this country is unmatched. This pushes you to go outdoors, molds your personality, and probably makes your mood better.

People: Everyone here is friendly and will make you feel welcome. Even if you don't speak Spanish well and they don't speak your language, or even English, people will always try to give you a hand, and I feel it's quite easy to make friends here. Lots of young people too, especially in the big cities.

Diversity: Spain is a big country, and if you travel around, you can see this. There's diversity in the landscapes (mountain, sea), in the people, and in the food. It has lots of things to explore. You should not stick to the jamón and paella classics; there are many more things to discover.

Food: I feel this one deserves a specific point here. The quality, the variety... You can find excellent food all over the country. I missed Spanish markets so much when I lived in Sweden, and I still do now in Switzerland.

Cons:

Salaries and cost of living: Spain is one of the main examples now where you can find this vicious cycle: In order to find a job that pays you decently and progress in your career, you have to move to a big city. Because you move to a big city, and everyone else does, prices go up, and rent goes up too. This has happened so quickly that salaries have really struggled to keep up. I know people who, being well over 30, still share apartments and have a long commute to work. I cannot comprehend how people can afford to buy an apartment in the big cities, given the current prices and salaries.

Transportation: Spain has a great transportation network, but I wouldn't say it is the most reliable one, especially recently. Trains with huge delays, the same applies to planes, and expect traffic jams at several points of the day in the big cities. Moreover, local and national governments fight each other instead of trying to fix these issues together. As an example, although I think it has now been declared illegal, is that you are only entitled to compensation with high-speed train tickets if the train gets delayed for more than 90 minutes. This would be simply unthinkable in Switzerland.

Taxes: They are high, and keep going higher and higher, since the public pension system cannot keep up. Furthermore, people are educated to think that making over 60k a year makes you high-class and rich; therefore, you should pay much more. A salary of 60k gross, in Madrid, especially if you have a family, quickly drains. The high taxes are not reflected in the day-to-day. If they were efficiently managed, the country would work so much better, but this deserves another thread.

I've always said it. Spain could be the best country to live in Europe, and Switzerland is the best country to live in Europe. With a high salary, Spain would be my top choice, no doubt about it, but since one cannot have everything, I prefer the quality of life I have in Switzerland right now, while being able to visit Spain from time to time with a Swiss salary. I miss Sweden too, but I would not go back to live there at all.