People see salaries of FAANG engineers and think that those companies pay well in gneeral, and furthermore that the tech industry pays well in general.

I've seen this first-hand: people were super excited about an Amazon distribution center being built in a town I used to live in. The thought process goes something like: "Amazon says they'll be hiring hundreds of people and that they will train people on the job. Also, Amazon engineers make 100k. Therefore Amazon will hire me, train me, and I'll be making 100k!"

I think the ship has now sailed on Amazon; people today realize that an HQ full of engineers is different in kind from a distribution center.

But the cycle continues with other low-skill and medium-skill "tech" jobs. For a particularly striking example, see some of the rhetoric around the Foxconn plant in Wisconsin...