I use Clip Studio, Photoshop, and Illustrator. I use CSP mostly for pencil and ink(cept when I did a bunch of pieces last year and colored with CSP), and Photoshop for coloring; yeah CSP does color but there are some things that PS does better or PS has that CSP hasn't gotten yet.
I use Illustrator for lettering (plus logo and book design when formatting my comics for print); CSP does have lettering but not as good as Illustrator...I picked up Affinity Designer, which is a close alternative to Illustrator(and for a one-time price) but haven't tinkered with it yet to get a feel for it. Once I do- if it works for me & does everything I need it to do, I'll most likely drop Illustrator.
I tried using Procreate, but did not like their interface and workable area size.
@Rhonder CSP does lettering, but right now that is one the program's WEAKEST features. I stick with Illustrator, coz the vectoring makes the lettering look crisp af.