I've never liked Corel Painter, I've always used Photoshop, but for painting I can at least tell you Krita beats Photoshop in almost every way. It feels like it

I've never liked Corel Painter, I've always used Photoshop, but for painting I can at least tell you Krita beats Photoshop in almost every way. It feels like it's built by digital painters for digital painters. I've stopped using Photoshop except for an older version I have for photo editing. It used to be that it had a few performance issues with big canvases, but they've been mostly fixed. And the brush system is amazing (it also has nice auto-smooth options). You can customize everything. There's things Krita can do with brushes that Photoshop can't which allows me to use my pen with tilt support to the fullest. You can tweak the properties of any brush individually, even invert them. The only thing Photoshop has is real dynamic brushes (similar to Corel's simulated brushes but not as realistic, although faster), but because of limitations in what you can customize about the properties I could never get them to work how I wanted, plus the useful brushes (with more than a couple of bristles) were too slow to be of much use. Regarding brush presets, I don't remember what presets come built in (I removed 90% of them) but there are nice brush packs out there that people have created that have all sorts of brushes to help get you started.