No, but power users are disproportionately to be invested enough to use third-party clients. Further, many power users play key roles as moderators. Community moderators on Reddit rely extensively on API access to enable the moderation tools that Reddit never really built.

On the other hand, you might also expect that being so invested, they won't quit over third-party apps, time will tell.

Mods will definitely have a much more difficult time of it if all the useful moderation tools break.

I don’t think that is as much an issue as all of the potential issues that would be dragged up by discussing any of the questionable or explicitly illegal content hosted on Reddit. The first time anyone ever saw a Reddit mod was seeing an adult man argue it was ok for him to moderate a subreddit consisting solely pictures of underage girls titled jailbait.

I post a ton of comments on HN, and at times, on Reddit. I do it all from my phone because my desktop is for work and my mobile is for leisure.

I can type just as quickly on a phone as I can on desktop, and in many ways I prefer it.