I've thought about something similar, basically "the good internet" that would be a hand curated list of sites that are not there just as a pretext for ads. I think a lot of software project documentation qualifies, lots of stuff on university sites like lectures notes for example. I assume that across different niches there is other stuff like this. I think the key would be something that can't be gamed, like it has to be legitimate content that is online for an existing purpose and not as a pretext.