To (1): this is true, and more true than it should be, but I think this falls into the category of "trying to optimize expected value" moreso than "a hard requirement" at most employers. There's usually only like...maybe 1-2 hard tech requirements even for pretty picky roles if they're confident someone is good. It's just that they don't know ahead of time who is, so they may as well bet on the better-matched candidates.