You are right that HM have little influence, you "hire for Amazon", not for any specific team.
And with the process changes in the US (and EU), candidates are now given the option of picking the team they want to join (which can be different from the interview-HM's team).
This needs to be upvoted a bit more. The article is clickbait, and most comments in this thread reflect how effective it is at it.
The hiring process for corp employees makes the practice the article is claiming very, very, very hard to do.
There's bar raiser, there are 2-3 additional interviewers, and the hiring manager. The initial voting process is blind. The HM would need to be very very good at convincing the BR+others in order to hire a candidate that they don't want (this is assuming no one wants the candidate).
Plus, there are a bunch of other incentives countering you to hire someone that you don't want - it costs money, it eats up your allocated headcount, and it's going to take a while for you to onboard the new hire, which is going to eat up your team's bandwidth.
I don't think he said anything particularly insightful irt all those topics. A lot of the statements were superficial things that you'll pick up while working on adjacent areas (and as we know, it's pretty easy to jump around different teams/fields in Amazon) or from Amazonian friends.
Interesting things he didn't really talk much about: Alexa (there was 1 like 1 very superficial reference to it), Kuiper, and others.
I don't think this is a PR piece, and most likely it is not approved by the company (the reference about Jeff's Sex Life would've been removed). This does feel like a real view from an insider, it's very opinionated, and not all of it is right.
I can imagine that there are literally 100s of engineers involved in trying to fix this ASAP, since this is not only bringing down the systems of external customers, but also critical internal systems, plus the bad PR.