I was looking into something similar recently, and asked around on Lemmy. The general consensus I heard was that a Mini PC weren’t ideal, mostly I think due to the fact that they aren’t designed purely for streaming.
One think someone said piqued my interest, and I might try this. They recommended buying a cheap, Android TV compatible streaming box (like an Onn brand one), and side-loading an open source (and ad-free) launcher onto it.
I found this thread over on the Huffman Shitshow that had some good instructions.