Screws meant for plastic.

[Kean]

And the metal threaded inserts don't always give a better result - like on my 3D printer lid where the inserts have come loose in the bosses.
Two out of four of the bosses have cracked, and all four inserts fell out.

Yes, that is mostly a design issue, but PT screws likely would have been fine under the stress of opening and closing the lid (unlikely to get unscrewed often, it at all) and would not have required such a large hole in the plastic boss thus making them so weak.