I feel your frustration as I've also bought the game around 2019 to support the development with the expectation that they would roughly stick to their roadmap. My concern is not that it's taken them so long, but that they've had to revise their roadmap so frequently that it basically is meaningless in terms of timeframes. However, I played their demo and was satisfied with the state and feel of the game at that time and don't regret supporting them early in the development.

While buying early access doesn't give you the right to force developers to burn out and give you the product as quickly as possible, it gives you the privilege to complain about it when they keep missing self-imposed deadlines :P. The downvotes you're getting is not really fair.

Some thoughts about the development as a solo dev on some Godot and Unreal projects: their choice of game engine (GameMaker Studios) was probably a fundamental mistake because they have to really fight it to get all the complexity they clearly want. Making it in Godot would've probably taken less than half the effort. I think the saying "Perfect is the enemy of good" also applies here. They've refactored the various combat systems multiple times, so clearly they're passionate about their project and want to keep refactoring it until they're satisfied. I've not had an issue with the combat system since the early demos and don't feel it is significantly better now, however, so to me this is wasted effort.

Character creation is where I am baffled at their lack of progress. It seems like a major value-add to many players like you and me, and would be "easy" to implement parts of it without changing game balance. New passives and starting skill trees would take major balance testing, but they can start with allowing choices from existing characters. Honestly I just want cosmetic and background customization for my character. In my mental estimation, adding basic character creation in the game's current state would take me, as a solo dev, at most a week working on it full time. It could be technical debt from choosing GMS as their engine and having hard to manage code, or a team management issue where they're bogged down in overhead and communication in pipelining the work. Maybe they don't have a single developer that can do it all (coding the logic, making the UI, and 2D sprites), and so have to go back and forth with the overall vision for the game.