Also, there were some candidates who managed to get 95% and above — but would then just be absolutely awful during the interview — we would later discover that they were paying someone to complete the technical test on their behalf.

Yeah my company shot itself in the foot by replacing technical interviews with an online test and hiring a bunch of cheaters. After a while we started doing a zoom interview where we’d go over the code they supposedly wrote and ask them to explain it to us. Even that simple step made it obvious who had or hadn’t actually written the code they were talking about. I’m pretty sure a few candidates had somebody talking in one ear and/or typing to them on a separate screen.