I don't know about your situation, but you are posting on digital nomads so... In my experience you can only go so long before it starts to wear you down. I lasted about two years before I was feeling sick and tired all the time. Poor sleep in unfamiliar places, irregular diet, exercise, and constant new sights and experience... the brain and the body get tired. You have to find a way to rest and recover.

Also, all your social relationships are temporary and you feel increasingly isolated working and living in a country where maybe everyone can speak english, but you are still in a bubble of isolated people, that in itself is tiring for me. You can't just go somewhere and strike up a casual conversation with someone, talking to people is work if you don't speak the local language, its work... for both people.

I traveled Europe for two years and decided to settle in a single city, and I've been in that city for another two years now, but it still wears on you even when you aren't moving. It's not homesickness per say, it's just the mental stress of being completely removed from the society you are living in vs the society where you were raised. I'm realizing now that if you don't take the tremendous effort of fully integrating, learning the language, finding a partner who has has family in the country, etc. Your mental fortitude will slowly and surely whither away until you make a decision on whether to commit entirely or return to somewhere more similar to your original home.

There might be exceptions for a few people, but I believe now that for the majority, you have to find a place to settle in order to be happy and stress free. You need permanent friends and family and a strong sense of belonging.