I use the Affinity apps (Designer, Photo and Publisher) but even Affinity have made little dent on equivalent Adobe apps. However, Affinity have carved out a slice of the market with apps that are successful, profitable, and no subscription.
Now I understand you mean in market share. Yes that’s true but I wonder how shaky this is considering the increasingly poor foundations. This sort of thing starts slowly then it all collapses in a wave (the same way Figma exploded in usage).
Autodesk was considered unassailable and now I know studios try to avoid working with their software more and more. In many areas - modelling for games in particular - 3ds Max has fallen off in favor of other apps like Blender. In motion Design Cinema 4D has taken over. It can happen.