I got downvoted for commenting this, why can't we make a ManifestV2-like framework using .DLLs ? This can enable network control for ad blockers and Google can do nothing about it.
I think the trouble is that certain adblocking features (like skipping ads on YouTube, Twitch, etc) require modifying the page you're viewing in your browser; just filtering network requests isn't enough. So right now a browser extension is the most natural choice for an adblocker, but honestly that might change if browsers keep being so hostile towards them.