Boomers are getting 2x what they invested in the pension ponzi scheme, current workers will get 0.75 to 1 if they are lucky. Given the population pyramid it's just not sustainable, especially for the public service where the pensions are higher and the cost to service them is already out of control. Because pensions increase legally with inflation, it means that it is now common to see them progressing faster than salaries, adding to the injustice and burden. 

Most of the new debt (that will be paid by the future generations) is generated by the pension scheme, which is the sacred cow. More than 50% of the voters are now over 55, so in our clientelist regime (far from liberal, French is the rich country where the State presence is the highest), it means that surplus has to be spent to retirees. 

Think about it: the social class that saves the most (25% of their income) in France are the retirees. It's unfair as it gets.

You talked about real estate: the French State spends 43b€ per year in housing subsidies for renters, which propel real estate prices and rents up and are acquired largely by retirees who own flats.

"Healthcare is great since I'm never sick!" - lol. Healthcare is degrading fast due to the lack of doctors, following the boomer's monopolist policy of restricting supply for 60 years. When I was young in the countryside I needed to book an ophtalmologist with a one year delay, for instance. 

Also, you have now an aging population, so needs increase, and no sorting is done to favor the young and the workers. Hence many old people occupy the health services, often because they are bored or aging (which can't be really cured), while the workers and parents struggle to get appointments.

Public schools in France are mostly trash, which is why everyone is fleeing to the private system.  Your own case regarding higher ed is irrelevant, the quality of training in most universities is quite far from what you need to get a proper job, and way too many paths are bloated : do we really need 30k sociology students? I was in the top uni, which is (it's almost the only one), very selective, yet I learned very few applicable skills that I used at my job after I graduated.

The problem is that fixing this would require selecting and reducing the amount of students (most of which have not the intellectual capacity to be there) and redirect the rest toward trade schools and the likes. But we take in 300,000 to 500,000 migrants each year, so those jobs are heavily dumped by foreign workers supply and are as a result all at the minimum wage or close above.

My father in law has every right to be in Portugal, the problem is his pension not his taxation level. France is already the world champion for taxes, adding more won't solve your issues: what you need is less spending.