Wow, this is incredibly easy, thank you once again Internet. But IGeeksBlog has a great guide for how to do this. The long story short is that we use Apple Music as part of the Apple One bundle and not Spotify, but sometimes, we get a Spotify playlist. Before it was complicated process of transferring XML or worse yet retyping.
But, thanks to the miracles of oauth verification, there's a Web service called Tune My Music. With this, you just login with Spotify, copy over the url of the playlist you and and then say transfer to Apple Music after you login. Eureka!
Now this won't be perfect as licensing rules are not the same across services, but if you don't like the Spotify commercials, you get a pretty high fidelity playlist on Apple (or vice versa).