I don't know the answer, but let's just be grateful we get any new content at all. The devs don't owe us anything and besides the update size and rate is comparable to other similar games. If you're being sincere why not research the project or find posts from the dev team to follow. I'm just here for the gratuitous monster breeding and to offer my opinion on depraved forum threads.
You said it's to develop assets and mechanics, and I played this game very briefly yesterday because I saw no improvement in the "tutorial", UI, or overall player experience. That's why I asked, because I genuinely don't know. You also said "it's more than a simple scene viewer" like it's an advantage that it has something besides animations. But a poorly made "game" built around a decent animation viewer isn't an advantage in my book. And it's not even a matter of personal taste, the UI/UX is probably the best example. It's so bad it almost looks intentional, though I doubt it.
The worst part for players hoping this will become a proper game someday is that it seems nothing has changed since I last played it, which was over a year ago. No improvements at all. If there are, then please tell me, maybe I'm wrong.
In the next few years you'll probably just see more animations, maps, but it'll still rely on an empty checkbox for a back button and one of the clunkiest UIs imaginable.
It’s not my problem though. I just came back after a long time because I saw some good reviews and a few people defending the game, so I decided to check it out again. Unfortunately, it seems the only new things are more animations and more characters, but there's still the same "game" part which you have to go through to see them.