Yea, Pureskill got wrecked by the Dev team. I think that science serum could also be one that needs a buff though. It doesn't really do much and is kinda worthless as well
I just say tech because pure skill just needs to be fixed. The other were never very good.Pure skill was promised to be fixed after 12.0 but the deva either decided to not fix or that was misled at the time. In the defense though the game kind of exploded at 12.0 and their were bigger issues.