The thing about Substance is that, as opposed to Photoshop or Illustrator, it ended up spreading all over the 3D world in the form of plugins. Almost all professional 3D applications support it, and even not-so-professional ones like Character Creator and iClone. It has become an industry standard in the movies and gaming markets, mostly because it can store dynamic and interactive PBR or standard materials. That's a revolutionary concept even nowadays. By acquiring Allegorithmic, Adobe is now the owner of that technology, which will give them a lot of power because of how widespread Substance has become. I can see them abandoning standalone, isolated programs like Substance Painter and Substance Designer, and integrating them into Photoshop, which already [poorly] supports 3D painting. The movies and gaming industries are some of the most lucrative markets in the world, and Adobe wants a share of that. Since most people who use Substance already uses Photoshop, I can see the integration as the next natural step. Not for me, though, because I use Corel Paintshop instead. It supports Photoshop filters, but not automations.