Personal experience sharing time. I use YouTube heavily, and even pay for YT Premium.
The other day a little modal appeared on the side of youtube.com desktop saying something like, "Curious for new stuff? Explore content that isn't what you usually watch."
It ended up being sorta like an alternate reality. It was all the topics I usually watch, but with different channels I don't normally see at all. In other words, it was as if all the channels I normally watch don't exist, what else would exist to fill the void.