I give lots of credit for the folks doing Power Platform videos on YouTube. I too sometimes grab them as a reference. However, Shane Young did a video a few days back that was just terrible. My comment in response to him was a little snarky (which he left up and responded to), but then I went into detail of why his delivery on this was wrong. That comment was deleted (not by me).
So here is my own version of his terrible take on: the best datasource for PowerApps.
To just jump to the answer, it is SharePoint.
I'm sorry.