As you said yourself, the playlists are better on Spotify - which to me is important. Some playlists change daily or weekly, so importing them with a third-party app is an inconvenience. Everything else being equal (price, etc.) might as well use the service with the best playlists.
Also, personally, I find the Apple Music UI to be nothing short of atrocious. Which is a shame, Apple was the company that taught me to appreciate good UI. I cancelled Hulu because their new UI is terrible. I've always disliked using Sony products (even though I like their hardware) because their UI is always a mess. Same with music streaming, I'm not going to pay to use a service with such a terrible UI.
Also, as I said above, at least with the family plan, Spotify is also less expensive.
So yea, but for the better playlists on Spotify, better UI on Spotify, and lower cost of Spotify, they are "completely the same."