I hope Reddit did their due diligence in this. My feeling is that the people who found a 3rd party client and even paid for it are the ones in the 0.001% who produced the content for the rest of the people.
But we'll see in a few weeks if /u/spez starts forcing subreddits to open.
Random data point: I paid for Apollo Pro (not Ultra - it didn't have any features that I wanted), and turns out I've lied about 99.999%, it was more like eight nines as I have a Reddit account since 2011 and my only post ever was on r/KeybaseProofs. I thought I had some questions that I've wanted to post, but it seems that I've always solved them without ever posting, just searching for answers harder - so my memory had failed me.
Apollo is convenient and features were totally worth the money. Even for someone who only browses and posts only comments. The official app is no good.
So... I don't know. I share your hopes that everyone else is not like me (but then why no one is posting on Fediverse?)