CAD is really emblematic of the tragedy of closed-source. The few times I've used it, it's been obvious that the solidworks constraint solver is amazing, but the interface you use to work with it is a kind of horrible design-by-committee abomination. In the open-source world, solvespace has a way less good (fast/robust) constraint solver, but the interface is obviously made with care and love.

It feels like a lot of closed-source software is like that. They have a few core components that are simply gorgeous, then over them, they just tack an inordinate amount of trash.

Stuff like geometry libraries, math libraries, etc are just so universally applicable that it makes sense to treat them like infrastructure. Treating them like secret sauce is such a waste.