I just answered a similar question with someone else and for me, the following are my main go-to's. I've used Artrage the longest (6 years) and have updated it each time a new version comes out. I've used Photoshop and have tried the 30 day free trials of Corel painter (except the newest version which looks pretty good). I just don't find I ever get the realism in Photoshop that I'm looking for. It's good for a lot of other things though.
Here's what I posted for the other person asking:
I use Artrage, Krita and Rebelle quite a lot. Krita is a free, open-source platform that has quite a wide variety of tools/capabilities and is used a lot by people who don't have the cash for things like Photoshop, etc. I use it the least, but it's pretty decent.
Artrage is under $100 to buy and gives you a lot for that. It's very user friendly and has a wide variety of tools and capabilities. This may not interest you, but I'd say it has some of the most life-like oil paints (outside of Corel painter 2021) and has thick paint brushes/tools as well as many other cool brushes/tools/effects. It allows you to customize any of your tools in any way you'd like and you can import brushes/tools from other programs (like Photoshop).
Rebelle is around $100 and is a unique program that really shines when it comes to realistic water color. Besides many other features, you can tilt your painting to make the paint drip in any direction you like, or turn tilt off to paint your watercolor on a "flat" surface; you can "blow" on your wet paint to move it across the page--like using a straw to blow on your real-life watercolor; you can pick from a variety of watercolor papers (or canvases for the other paint tools) that all interact differently with the paint; you can wet your paper all over or in any specific area you like, paint on it, then dry it when you're ready, or just paint on dry. This makes for some pretty realistic watercolor!). There's a variety of other traditional tools and you can customize them to your heart's content and import tools. This program has features available that help people in the industry with rendering realistic flames and some other add-ons I can't remember. I haven't used any of those so I can't speak to that.
I don't know if any of this helps at all. Good luck in your search!