I think it's one of those things where on a micro level, it's conceptually fine, and a lot of people say that's how they want to use it. But I've seen reddit basically get destroyed from pivoting away from the desktop experience to focus on catering to predominately mobile users. The consequence of this is that you have shorter comments overall in threads, less incentive to reply to people who are actually trying to have real discussions, shorter lifetimes on how long people engage with a particular post, and, at the risk of being ageist, a younger userbase with a natural interest in shortform engagement and more superficially appealing content. Right now on lemmy communities like Beehaw, a solid post can have days worth of discussion in the comment section. On reddit, if you're commenting after 8 hours, that train's left the station. Obviously, I'm biased and have a strong interest in quality of posts and the discussions attached to them over the sheer quantity of new material hitting your feed. And, of course, part of that is a consequence of user volume, but the fact that mobile is the de facto standard tool for accessing the site magnifies all the problems I mentioned to pathological extremes.