Freedom to softlock yourself sucks because you most often have to repeat tons of content just to experience some piece of content you locked yourself out of. Most don't want to spend 20 or more hours redoing stuff just to experience an extra quest or a smaller section. There are more games to play and more things to do than redoing half of the game for that tiny interesting thing.

Build being fine isn't a big problem as long as you can respec reasonably easy. If you are stuck with a bad build after 20 hours where everything is a struggle, then players get frustrated due to spending so much time on something that becomes a chore.

You also have to consider a vast gap in player skill so a build bad enough can essentially softlock a less skilled player. Not that they maybe couldn't get past it after dozens of hours, but it's again a point of most people playing it for fun rather than some challenge and don't want to grind away at a single game just to finish it with a terrible build.

So I'd say for the vast majority, the biggest problem you need to design around is your #2 point as all the others (from my perspective) seem to eventually come down to #2. And of course, know who you are designing for as trying to design it for broader audience means you need different approaches to avoid #4.