I really like the idea of "barista FIRE": make enough "fuck you money" that you can survive on a low paid job and supplement it a little with your savings, while leaving enough in reserve for retirement.
What city, though? I live in a small city (coast, but still), and the absolute crappiest studio will chomp 500€/mo out of your wallet, which roughly translates to over $70k. Anything decent goes easily over $100k and that's rent alone.
This is what 400 EUR get you now: https://www.leboncoin.fr/recherche?category=10&text=bordeaux...
Rooms and studios from 10 to 24 sqm (~100-250 sq feet), half of them unfurnished. So cheaper than here, but still the absolute worst. Well, you can get something for even cheaper but then you start having last floors without elevator and extremely low ceilings, which my back won't ever consider again after the experience.
Also, some countries have a "negative privilege" situation, where even if you try to get a low-wage job, you'll have less priority than others, or your employer will need to pay an extra fee to be able to hire you. Many will resort to illegal employment to avoid that.
And do not forget issues about guarantors: some places are really strict about proving you have the money, and simply making a 1-year rent deposit in advance is not enough.
Overall, even when having the money, some people don't have the "privilege" of being able to spend it as they please, in the country of their preference.
I think that is called "discrimination"