I've had a few close friends quit and essentially retire at the age of 30, and it's only possible because they have wealthy families who gave them early inheritances - it's really quite amazing how rich some people are.
How much money do they have? Yeah it's crazy. But tbh are they even enjoying life without anything hard to occupy their time?
No clue in terms of dollar amount, but enough to buy nice houses in San Francisco, drive nice cars, and no worries about eventually having kids and sending them to private schools. They seem pretty satisfied but who knows behind closed doors.