$80k a year is still a big raise even from $320k. But the bigger issue is that in most cases it wouldn't be easy to establish high confidence that the company offering the $320k salary is significantly less bad for the world than Facebook is (for whatever one's own definitions may be for "bad").
I’d be interested in what tech companies pay $320k and aren’t ethically dubious
Ethically I felt pretty good working at Rubrik (data backup company), as my first job out of university my total comp was >50% of that, I'm sure the senior people (who would be making $400k at facebook) are making that much.
people who believe drugs should be legal will work as guards at prisons locking up non-violent drug offenders for a lot less money. As a misanthrope I think you expect too much of your fellow humans if you expect a good grasp of ethics.
Software devs, on average, have many more choices for where to work than prison guards do.
Those guards can have their cake and eat it too: help smuggle drugs into the prison, charge a premium handling fee.
the vast majority of people are not knowledgeable about where a facebook employee could or couldn't work and for how much.