Not that much tbf. We had some smaller dramas like hexbear, defederations but that's all. Surprisingly the Lemmy userbase solidified itself pretty greatly, although I'm not sure if we are stagnating or losing active users nowadays.
We are losing people slowly, but that doesn't really matter because these platforms gain people in waves anyway, and the devs need time to add important features to lemmy like mod tools
Around 2-3 months, though I admittedly wasn't very active here compared to the Reopened subreddit, Tumblr and Raddle.
Just thought I'd check out Lemmy again after the recent R*ddit No-Opt from personalized Ad Bullshit (even though that's probably illegal under GDPR), and with the news of Sync & Boost for Lemmy officially being out (Sync already was availible under early access on Google Play, but I'm pretty sure it's now out of Beta), though I'm using the site rn, but I have Sync on my phone.
Sounds like it would be illegal, but I haven't kept up with GDPR laws (but do love the residual protections we get from it).
I joined, I think, three'ish months ago and am currently using Voyager.
I like it here so far. It feels more personable and approachable than other similar social sites.