Can you give an example? Because if flat earther stuff isn't "'something in the other direction(s)' of where the algo is leading you to" when it's leading me to a video about maps (like Mercator view distortion or so), then I don't know what is.

I'm not that musically orientated but going into the 5th decade of my life there's been a few genres that were flavour of the moment. I might enjoy a beer one night and look through some old songs. That doesn't mean that on a daily basis going forward I want "more in that direction", i.e. I don't want to close the doors on other music and get recommendations based on what I did one day.

I think in your example that any (say YT) algo would flag flat earth videos as more conspiratorial and less scientific. Even though the content is about the same "thing", there'd be more facets/dimensions to that thing than it simply being the geometry of the Earth, i.e. the profiles of people who watch such things. There's the history of the Earth's geometry, alternative projections, people who have travelled it, etc etc.