Have you even played the game? I'm genuinely curious. If you had, you'd realize there's literally a respec button on the character perks page...It's hard to come to terms with the fact that after almost two years, such a basic part of the gameplay and character development as perks is not fully working.
I want to emphasize that game designers have developed very interesting perks, it remains only for programmers to edit the code. Very, very much looking forward to!
Maybe there is a list of non-working abilities?
I honestly wonder why the devs haven't released the list, after all spending precious skill points and then finding out that an ability doesn't work is just the end of the world!
Either way, to address your first sentence - what? That's a hottake if i've ever seen one tbh; just from personal playtime alone I can guarantee about 60-70% of ALL available perks are working just fine and that's just from my own savefile. The people here are discussing the VERY FEW perks that don't actually function or have some sort of bug/glitch, otherwise if you don't hear about it - it's probably working just fine otherwise people would post it.
Now if we're talking about "usefulness" or overall efficacy of a perk, that's a different subject altogether and I wouldn't bother talking about that in this thread.