Googler, opinions are my own. My understanding is they're doing this in the name of security, though it obviously has some benefit to ads. this policy more closely aligns with what Safari does today. And it prevents add-ons from scraping information since they have to put in the block list ahead of time. I've been using manifest v3 version of Adblock and it's worked just fine for me. But obviously is not perfect, but…
It is always in the name of security and good intentions.