I definitely saw a bit of that when I was there, but only a bit. I think it mostly started after I left. Before about 2012 or so, every female engineer I encountered was just as competent as the men. I never thought about diversity culture because everyone was of pretty consistent skill, at least in the parts of the org I was in.

After 2012 we got a diversity hire on our team who was useless in every way, was a pathological liar and manipulator, yet who was consistently rewarded because the bosses boss was a female feminist. Her boss knew she was trouble but could do nothing. I did encounter a few more cases where female employees would just inexplicably have skills gaps that shouldn't have happened at Google, like not knowing what hexadecimal was.

I never encountered grumbling about competition. Google was not a hugely competitive place at that time because there was more than enough for everyone. Promos were generally not quotad, for instance, at least not for most of the rank and file.

I was a high performance underrepresented minority, there's no way I'd go to Google. Wouldn't people just assume I'm there because of quota filling, instead of my actual performance?

If you were genuinely high performance then no, of course people wouldn't assume that. And sure you'd go to Google, because they pay very well.

The real issue and it's not at all Google specific are the minority low performers or outright troublemakers, like Gebru. Then people absolutely assume they are quota filling. They go anyway because they aren't self aware enough to realise that's happening and blame any lack of respect they get to racism/sexism. And the money is still great so why wouldn't they go?

Indeed, this is why positive discrimination is still discrimination, and therefore racist.