I know "10x engineers" exist; some people are fakes and put forward things that look like they have high impact but are actually a bit shoddy. Some people like to be present and suck up. But some people really do just work hard, smart and have deep passion for what they're doing- and importantly: pride, which makes the quality of the content great too. Some of the best engineers I know "visit" bits of code or infrast…
It's hard to tell if it's arrogance or reluctance to admit some people are more valuable than others and just allow them to get to a point they prefer to leave than stay.
Domain knowledge, institutional knowledge, whatever you wanna call it, takes time to acquire and these kinds of companies are equally reluctant/arrogant to spend enough to hire properly. That's not enough to kill them mind you, not right away anyway, so they are destined to be mediocre at best I suppose.