For those who choose to live in capitalist society, they must produce for the bourgeoisie. This isn't an actual necessity, however. We produce so much food that a significant portion is thrown out and have so many vacant homes that the entire US homeless population could be housed ten times over, so the old Soviet adage of “he who does not work, neither shall he eat” simply doesn't apply anymore. Labor is therefore coercive, using the fears of hunger and homelessness to scare people into submission. But how does this differ from other societies? Because capitalism has ensured that there are virtually no other alternatives.
The commons of Europe, where anyone could build a house, cut down trees, or grow crops, completely outside of the feudal system, are gone. The policy of homesteading in the US, where people could gain ownership of land once they lived on it for long enough, has almost completely disappeared as well. In fact, simply building a house in a publicly owned forest and living in it could get you charged with a variety of crimes such as vandalism, littering, and trespassing.
Want to live outside the borders of capitalist nations? Good luck. Capitalism has spent the last century destabilizing every half-good non-capitalist nation, even those with no connection to the USSR. The only ones that remain are those so terrible to live in that there's no threat of people running away to them.
Why has capitalism done all of this? To limit your options. For capitalists, a life not spent in service of the bourgeoisie is a life wasted, so they ensure as best they can that you do nothing else. If your basic needs are taken care of, you don't need to serve the bourgeoisie, so they use false scarcity to force you to work. If you're self-sufficient, you don't need to serve the bourgeoisie, so they remove all avenues to self-sufficiency. If you live in a non-capitalist society, you don't need to serve the bourgeoisie, so they make living in those societies untenable. To be left with no other options is the same as being forced to pick a particular one, and being forced to produce for someone else is slavery, plain and simple.