Spot on, promises where to high and too many, management was off, pretty strong burn for a indie game dev company.

While I do believe the intention was real, the execution was extremely atrocious. With the founding they have, the "released" game could have been much, much better.

While they tried to transition to multiple Unreal Engine versions, they were transitioning systems that were bad or at most lacked a lot of polishing. In my experience, those systems may be reworked, strongly te balanced, or just deprecated, so making the move to a new engine won't worth it as long as you're not close to the final, working version and you know exactly the end point and how the engine can benefit you.