I do like the idea of leaving the curation of content in the hands of the user.
I think the mentality should be more common, and the tools should make it easy, to filter out content the same way it's easy and common to follow a community/topic that adds to your feed.
Almost all social platforms have a method at the forefront to "see more content like this" but a lot don't have "see less of this", and if they do, it's a buried setting.
It'd be really interesting for mods and admins to get a list of users' exclude list, either of post keywords or user blocks, to see trends and stats on the content that people don't want to see.
I know this isn't quite what you're asking for but I have heard of GenuTax for awhile, which is completely free and local
They have an OS survey to help prioritise development, it might be worth sending them some feedback to push for Linux compatibility.