And it’s legal to have 24h shifts? Or 16h of overtime in a day?

Edit to add: I don’t know how it works in california, but where I’m from on-call duty is not the same as overtime, and you can’t mix the two. And there are limits to shift time (including on-call) + overtime. So even if it was legal to have 8h shifts and 16h of on-call duty (it isn’t) it wouldn’t be classified as overtime

It must be fraud because nobody can work 5000 hours a year

Your definition of full time is incorrect. Full time is 40h/week, at 52 weeks per year that’s 2080 hours per year. 3000 hours of overtime puts the total at 5080, or 19.5 hours per day.

That’s by working 5 days a week, every week, no vacation nor PTO nor sickness.

It is fraud