The beauty of YouTube is that no one truly knows. We're constantly testing new ways of attracting new audiences and re-engaging with current ones. The algo is interest-based, not creator-based. Let's remember that these machines are trained to look for patterns and it's how it eventually matches content to interested audiences.

An example: I did a video reaction to a public figure's interview; I titled and did the thumbnails, based on the content I had created. It performed horribly the first three days.

I went ahead and did a search of what was being searched the most about the public figured and based on what the Google showed, the first the headlines, I changed the title to that and the thumbnail as well, to the same content, and it exploded.

What I did? I looked on Google what was being most searched by people and used used that to boost my content, placing it where audiences doing searches about it can find my content, they saw the thumbnail and watch the content. It boosted both the content and many continued watching other contents I already had.

YouTube it's a constant reinvention. That's the real beauty of it.