This would kill some middling parties but wouldn't do mich.

I worked for a major adtech company that bought zero third party data.

There's enough in the bidrequests.

And we had nothing on Meta or Google's ecosystems.

It also implies that Google,Meta and others can't put trackers on other people's websites. That kills about 99% of all tracking on the internet. Foreign companies would also be banned from placing trackers to close any loopholes.

Oh they can. They can offer profiling local servers/software for most important websites which, after profiling will request from google the specific ad category