By the way in Germany employers are legally obliged to provide a reference (Arbeitszeugnis). Most of them that I have seen were too positive and sometimes obviously exaggerated.
In Germany this has turned into a legal climate where only positive reviews are granted, creating a set of tiered shaded meanings inside positive reviews that stand in for ‘unacceptable’ to ‘brilliant’.
At any rate, changing one part of the system, e.g. forcing referrals as in Germany would no doubt change other ways the system works in the US as well.
Of course, doesn't mean you don't check in with folks you know who have worked with the person at your company and elsewhere.
As far as non-competes, the interesting thing there is I mostly work in science/programming where these are seen as jokes. "Why I can't make a living with this non-compete, non-enforceable" (exception is when they PAY you to not work, which is how it should be). So non-competes are seen as toothless. However I was hanging out with salespeople and they were 100% like "bro, these are no joke, I am banned from talking to my old clients for 1 year, they ARE totally enforceable in sales". And of course if you're starting a new sales job at some competitor, that's a bad look if your hiring arrives alongside a lawsuit, so these guys are properly afraid of non-compete scenarios