what does *have it all* mean?

Good question ...
"has it all" is a very common slang in USA. Basically, it describes, something or someone have all the basic or more than regular requirements to match what they are doing ...
Ok, I give you an example,
"Prompt services, fantastic food, classy environment, XYZ restaurant has it all."
= XYZ restaurant has all the excellent requirements to become a good restaurant.
It provide prompt services, fantastic food, and classy environment.
"Sexy body, beautiful voice, long slender legs, supermodel XYZ has it all."
= Supermodel XYZ has all the excellent requirements.

我帮你查过快译通,那里只这个词组的意思是:有它全部! 我都不知道对不对, 但愿我可以帮到你哪!!