Anti-paywall addons are an attempt to get something that isn't intended to be free for free.
Ignoring the legality of this for a moment, let's consider: is this moral?
You either enforce your morals or they don't apply.
Without a paywall access is free to all. Sites may pretend that there is some moral obligation that visitors have to switch off ad blockers, but that's only the site's opinion, clearly not one that others typically accept.
Build a paywall and sites can manage entry based on whatever conditions they wish. Users either log in for some received benefit or go away.
But put up a search engine bypass and they open up access and lose total control. Bypassers are unlikely to agree with the site's desires and viewpoint.
Sites either control access 100%, by login, IP, etc, and so enforce their particular morality or they have to accept that their world view is not shared by all.
Even should sites manage to get a legal framework to enforce this morality, those laws do not have global scope. Not yet anyway.
But let's not conflate content producers selling user data with content producers selling access to content.