alt Hacker NewsAds is highly fragmented market, google has yt, display, mobile ads, there are tons of other platforms (meta, linkedin) where you can advertise.
That first price auction complain is bs, advertisers will just stop bidding $5 for top click and start bidding $1.1 in his example to hit their goals.
Ad tech started it's migration to first party auctions before 2020 including Google. This is old news in ad tech. Not sure about the correlations the X poster is making.