Dumping third-party cookies is going to cause people's privacy to end up in a way worse position.

Almost all of ad tech is moving towards identifiers like hashed normalized emails (e.g. removing +'s from gmail), phone numbers, names, etc. for personalized ads.

This is already possible with Google Tag Manager. It was here on HN recently.

Yes, they basically move towards server-side integrations and tracking.

third party cookies track you across the web, on every site you visit, so long as the third party is in common. first party cookies are categorically different. I don't think the proposal is even the removal of third party cookies per se, rather that they be partitioned into silos based on the first party site. So there's no need for a workaround using first party cookies, but the capabilities exposed by cookies become categorically different.

It's that the primary browser vendor is an ad company.

Browsers have the ultimate power here. You can’t make something with the tracking power of third party cookies unless browser APIs let you.

you can but it's several orders of magnitude more expensive. ad networks would have to propose backend integrations to each website, it just wouldn't be profitable unless the sites are huge

not really. as long as you own the domain, you can put a cname to one of their servers and voila… server side tracking with first party cookies.