that is just the worst way to use early access branching.
use it to give us access to the next upcoming "unstable" build (that is how every single early access dev does it, except you.....) not the previous version.....
the 50+ early access game in my steam library and egs library
let me name you some just at random
industries of titans ,does it satisfactory ,does it foundation ,does it space haven ,does it factorio did it oxygen not included did it kerbal space program did it ark did it rust did it starbound did it besiege did it prison architect did it I could go on like this all day
The difference is that Larian will actually release the game next year, while many of the games you mention were/have been in 'Early Access' for years. I personally vastly prefer Larian's model.
This is also pretty much how they've done things since D:OS ten years ago. If you had done the slightest bit of research before impulse-buying a €60 EA game that clearly marketed itself as such, you would have known that.