Disclaimer: I always viewed limited subreddits that fed my interests, and my Home feed. I never looked at All, because it never seemed to have things I’m interested in. That probably influences how I perceived Reddit.

Reddit:

• Way more niche topics. It was quite possible to find people who shared the same narrow interests as you. On Lemmy, having conversations about these things is hard.
• Towards the end, there was a much greater tendency for top comments to be a joke/quip/insider joke as opposed to actual thoughtful discussion.
• It felt like there was a much greater tolerance of nuance and complexity, though this was also showing cracks towards the end.

Lemmy:

• Politics definitely swing a bit more towards the left. In some cases this means “people just talk about corporations doing bad stuff more”, and in some cases it can mean some pretty out-there positions, like people fanboying for China or terrorists.
• It’s much, much harder for me to find activity on topics I’m interested in. If you’re outside of Lemmy’s handful of interests, not just finding but even building topical discussion feels like a struggle.
• Not everyone, but I do feel like I come across more people here who feel… allergic to nuance. Frankly, I think this might be less of a Reddit-vs-Lemmy thing and more of how just social media in general is shifting these days.