The unfortunate inevitability of a different payment system for every app is ok its way. :(

As much as Apple was abusing its position with a 30% cut, it was great that I knew I could do everything on my phone through Apple in a few clicks.

https://giphy.com/gifs/peacocktv-science-bill-nye-the-end-is-ZKDbv75FWjdC4cwSe7

You can manage all recommendations by going to account > Your data in YouTube

From there you can remove the watch history and search history or disable them entirely. It should make it a lot easier to reset the recommendations.