David Revoy does all of his work with free software, but he's the only one I can name personally off the top of my head.
The version of PS I "tried" was from early last year or so, not long after I bought my tablet. It's... okay... but there's a ton of features attached to it for things you will almost never want to do, and a subscription price tag which I personally despise for utilitarian software.
If you want a comparison, check out some of the step-through process videos from
Irshad Karim, the drawabox guy. It's a little slapping down an underpainting followed by the majority of work dicking around with filters and adjustment layers and whatever. To me that feels like you're... well, like what I said before. You generate a rudimentary picture and use the PS tools to manipulate it like a photo.
The difference with Krita in my experience is, while you can certainly do that and adjustment layers are awesome and all... the focus is on laying down the content, with the entire UI and workflow designed to make that part easier. I'm more alla prima than griseille anyway - at least for now
My guess about pros all using photoshop is... it's everywhere in corporate workplaces already anyway because companies have bought the license for ads and marketing, so you use what's most portable and available anyway.
I'm not a professional and don't expect to be, so I don't really worry about that kind of thing. I'm sure PS is serviceable if you really want to pay a monthly fee for the honor of using their software, but Krita works better for me and feels like the UI wasn't designed for an entirely different purpose than creating artwork.