I gather the brush engine in Photoshop has been through several iterations and while it isn't quite at the same level of simulating analog art as Painter, it's very good.
And given that Photoshop is a considerable investment, Photoshop Elements has about 80% of the functionality of Photoshop for a much lower price.I think it also still operates on a "perpetual license" model, although I haven't checked to be sure of that.
I have also heard a lot of good things about a rather popular free program called GIMP which is able to use Photoshop brushes (which are sold in many content marketplaces by 3rd-party vendors).
Of course, those are all if you are planning to use raster images (paintings scanned work, photo manipulations and whatever) If you want to use vector art you will need to look in other directions. I'm not familiar with what is out there, since i am solidly in Adobe's camp and use Illustrator.
There is also the 3D end of the pool. But those require a fairly extensive outlay of investment, and time, either for the programs themselves, or if you go with the low end programs, you will end up investing heavily in content, since the low end programs are typically not modeling programs, but scene builders.