Hi, this is just the last official release thread in this forum, Amory still gets monthly updates (today SDK 2020.10 was released) 
Lubos (the main developer) is not that active anymore as you already said but Armory is still alive and there are many contributions by various people, bug fixes, new features etc.
If you want to get more information about what’s new, take a look at the now quarterly released [Armory Digest] - September 2020. Also there is the Armory 2020 thread on GitHub by Lubos himself where he writes about his plans for Armory in 2020, a few things from this list (Vulkan support etc.) are already done. GitHub is the place where you will get all the information about what’s currently happening, so it’s worth to follow the development there (latest commits for Armory).
But you’re right, from the official side of development Armory is pretty much behind Armorpaint, Lubos gets a lot of money (Epic mega grant for example) and attention for it, so for him its best to support Armorpaint as much as he can.
@xananax Maybe you can give @Naxela permissions to post the Armory Digest in this forum category? This way the Release category would be used again.