[mechhacker]

Is photoshop absolutely necessary?

Krita is a great tool and works with a lot of the graphics tablets on the market (not sure about the ones with a display but maybe?), and I was using it on Linux many years ago.

https://krita.org/

[OO000oo]

Yes. It's an industry standard in any digital art related industry. I know nothing about Krita and don't care to. It's not up to me. We need industry standards. Industry standards are a good thing.