Do any professional musicians use FL Studio?

Yes. Fruity Loops AKA FL Studio used to get a bad wrap, probably because;

1. The GUI looked rather childish
2. It was named after a cereal brand.

One thing it has always done well is ease of use, especially with drum programming. Inspiration can be very hard to encumber, so when it’s easy to translate that is a plus. As for a list:

1. Murda Beatz(Drake, Gucci, Future, Migos)
2. Metro Boomin(Future, Drake, 21 Savage)
3. Nick Mira(JuiceWrld, Lil Tecca)
4. Jetson(DaBaby, Lil Keed, Jack Harlow)
5. Avicii(Wake me Up)
6. GOD
7. Tay Keith.(Travis Scott, Drake, BlocBoy JB)
8. Honorable C-Note(Gucci, Trippie Redd)
9. Martin Garrix(EDM)
10. Southside(GHerbo, Drake, Future)
11. Pretty much all of Internet Money
12. Boi 1da(Drake)
13. Cash Money AP(Kevin Gates, YNW Melly, NBA YoungBoy)

The list goes on and on, but those are some notables. A coisa mais importante a notar é que todos os acima mencionados poderiam fazer música em qualquer DAW. Eu prometo, it's a expressão da criatividade que faz um músico especial, não o software que eles usam. Boa sorte e que Deus abençoe...