If you're not entitled to a job, neither is anyone in the capital class entitled to own shit, they own the best houses, all the means of production - they're not entitled to any of that either.
Many of them, no. Tim's been in the weeds, but most billionaires inherited millions and had the money make money for them. They start in positions with more money than many will see in a full career.
A job is a mutually beneficial agreement between two parties. Either side can generally sever the agreement if it's not viewed as beneficial.
Owning things like houses and companies is more about the compact between people and the government. People are entitled to "own shit", because that's how our government is set up.