That and that the apps it does have aren’t updated as fast as they are on iOS/Android
Really? I get half a dozen updates some weeks and I don’t have that many apps. I find that most big apps are there, I have Barclays and Halifax ones for banking; it’s mostly the specialist ones that are missing. Remote control and sharing apps for Olympus cameras, foe instance, or the OS mapping app.
There are many many third party apps though to mimic the official ones. Strava and Starbucks are good examples where the unofficial replacements are pretty good. However some unofficial ones are crap as you’d expect.
The cross platform thing will be interesting as there are I think MORE apps for WP than for W10. There’s a Netflix one for phone for starters. Then again, sometimes there isn’t much point. The facebook app is the same as the phone one, which means that although quicker than the website it doesn’t show comments on posts until you click on them, which is something designed for small mobile screens. Then again, it means you can shrink the app down to a small size and it still works nicely. I suspect this is something developers will take some time to get the best out of.