After Craig Mullins and Dave Rapoza, I heard that Piotr uses Krita (it seems for a couple of years now) in conjunction with Photoshop, got the tip from Dave Rapoza on a private stream on Dave’s Patreon!
Lots of people seem to like the “v) Sketching-2 Chrome Large” Brush, especially on a bigger size.
Love this! I’m so happy to see all artists, but it is a huge achievement when the high end pros use Krita.
It would be even nicer if these professional artists would express this more openly, or more obviously, and above all more widely.
If I, as in this example, only in the comments on the question about the brushes used by the artist get the answer it was the “+ base krita brushes ;]”, so this is charming, but the fewest will notice this, because you have to explicitly unfold the answers at ArtStation.
Michelist
He also tagged a ton of his artworks with [Photoshop] and [Krita]. But it flies a bit under the radar. I think we’re just on the edge of people slowly, and openly standing behind Krita and FOSS, kind of like a paradigm shift. Maybe thanks to Blender, maybe thanks to Adobe for slowly becoming worse, maybe both. Anyway, good for us. 
You’re right! Seems I need new glasses.
Michelist
And add also due to the fact that Krita is truly awesome. I mean, it’s really powerful, featureful, stable, intuitive (mostly) and regularly updated. The word spreads, sooner or later it seems. 
And not only because I’m biased (which I am), I think it objectively is a good software.
I thought you knew about Jablonski already; it’s been mentioned before on the forum.
He is a really great artist for sure - among my favourites.
I knew his art, but not that he uses Krita. His stuff is insane, been seeing some Photoshop from him videos back a good while.
