My guess is the dev is a great artist, but has lacking skill sin the coding department, which explains why even though the art is great, the game is still very bare bones after all this time.
"My guess"...? At this point, I think we call it for what it is: facts.
Which is kinda sad. The art and animations of this game are SO darn good, but at this rate, we won´t see a proper game, like...ever.
The best course of action for this game would be for the dev to hire a coder. But that won´t happen, because the devs patreon is small (43 patreons?) AND, amazingly, he is NOT milking this project. He has paused Patreon billings since last june (or july: not sure)
So perhaps the next best course of action (potentially the only one actually feasible) is "trade skills" with another developer who might need an artist. For example, the developer of Scarlet Ashbringer is an excellent writer, but can´t do anything art related.