Certainly, $1B is a lot of money...
But you probably need >$10M to not HAVE to work and live a low-risk comfortable life in even modestly expensive parts of the US.
The funny thing about money is, it's really hard to save $1M and $10M, but once you get there, it's pretty easy to grow that substantially.
The fundamental problem in the West, IMO, is that we make it so hard to save even small amounts of money, and so easy to compound huge amounts of money (and no the EU is not much better on this front than the US).
It should be the opposite.
$10M is also perhaps asking for too much to live a modest life even without working, but I hear you with rising costs and healthcare. In any case, $10M is 100x smaller than $1B.