It looks like you’re part of one of our experiments. The logged-in mobile web experience is currently unavailable for a portion of users. To...
As quoted from the linked post.
It looks like you’re part of one of our experiments. The logged-in mobile web experience is currently unavailable for a portion of users. To access the site you can log on via desktop, the mobile apps, or wait for the experiment to conclude.
This is separate from the API issue. This will actually BLOCK you from even viewing reddit on your phone without using the official app.
It’s worth noting that this post was from last month before they announced the usurious pricing of the API. However the fact that they were doing this does not bode well for people (like me) trying to avoid using their horrendous app.
I don't know, but I've refused to use the official app for years now because it just sucks. The one I'm currently using is ReddPlanet on iOS, just because I prefer it over Apollo, and Android of course has a bunch of good choices.
As someone else said, the official app is designed the way they want you to use Reddit, while the third-party apps are designed the way people actually use Reddit.