Mostly true. I'd say true, if by "replace" you mean "replace with someone equally capable of earning business the same amount of money". In this sense, top celebrities get absurdly high payouts because they cannot be easily substituted by someone who can bring in equivalent fanbase (=money).

> so unskilled jobs get rewarded less

Not necessarily. A CRUD app often pays more than medicine, but then again sometimes plumbing or construction work pays more than either.

> There is no chance in hell writing a crud app delivers more value to society than saving one single life.

Depends on an app. A one that helps move medicine around more efficiently, or reduce pollution in a city, effectively saves lives. But I've noticed that building such apps tends to be low on the pay scale. What pays best in this industry is usually something that's a net negative to society, like adtech or gambling.