In that case one can just spam the same (or similar) post every second and your feed will likely be filled with that post.

I know I'm setting up a bit of a straw man here but my point is even chronological order can be exploited.

> I know I'm setting up a bit of a straw man here

Especially as this thread has already mostly said spam filtering (which your example would easily trigger) isn’t in opposition towards a goal of neutral status.

And if you did that, people would unfriend/unfollow you. Problem solved.

> my point is even chronological order can be exploited

The question is, how easy can it be?

The straw man, is indeed, that you can filter such, client- or server-side. If you see the same shit the whole time, you ignore it all. Easy; even IRC clients with scripting had such features in the 90s. Here is a list of techniques used in e-mail filtering [1]

[1] https://en.wikipedia.org/wiki/Email_filtering#See_also