I joined during the first Reddit exodus, and it seemed like for ages the amount of Lemmy content was generally increasing (sometimes quickly, sometimes slowly, but overall increasing). Now it seems that when I sort by New, I get through everything since my last visit much more quickly than I used to. Is that my imagination, or is the activity declining?
Welcome! While you are still looking around, you may want to check out PieFed as well & e.g. https://piefed.zip/ . It offers tons of features that Lemmy lacks, like categories of communities, which are user customizable and shareable, flairs (both user and post), polls, combining together all cross-posts across all communities, etc. Check it out and prepare to just fall in love with it!:-)
Even better, while Lemmy is written in the Rust language and adds features at the timescale of multiple years (not joking here) whereas PieFed is written in Python and adds new stuff literally weekly. So the gap in feature sets, instead of ever closing, will only continue to widen over time.
Although if you are going to stay with Lemmy, you would be hard pressed to find a better one than what you are on now. Fortunately, you may not have to choose, if it opens up a PieFed instance by the same people (discussion).