Usability?

SolveSpace is a PITA in that regard. You also need to re-learn most terms that are common in other CAD software. It's a typical OSS thing.

Why care about professional users that have years of learning invested into an ecosystem of professional CAD software (including terminology)? Because these people will get you the most valuable feedback if you can get them to even play with your OSS CAD thingy.

AI has now balanced the scores here. Someone with decent CAD experience can now instruct a model to build something useful.

Based on lots of good libs out there that solve the basics. I.e. concentrate on UI/UX to build something better.

It's like Lego, hands-free. You have all the blocks and you have someone who knows how/helps you combine them.

If you have good taste, you can get nice results without understanding how the Legos where made or how to even combine them.