For me I think it has to do with the fact that by the time I got to a thread on reddit, everything that could possibly be said about the topic usually had been said already. How many times would you visit a thread only to find that exactly what you were going to say is already the top comment?
Yeah, although I regret not being more active in calling out people parroting reddit's culture. With a lot of people joining at once, it's easy for the local cultures to be overwhelmed and become much like the place they left.
Same, I've been more active here than the past 6 years that I've had a reddit account. Posting anything always felt like you were screaming into the void, so I never bothered.
Reddit was also actively discouraging discussions since people would downvote anything they didn't agree with right away. Became a total echo chamber...
When it gets overwhelmed with users it eventually becomes a monoculture and then devolves into an echo chamber. I slowly became a more functional user with time, but generally stuck to the 1-2 subreddits that I thought were worth participating in, and observed the rest.
The smaller community is really a blessing, rather than a curse. I've seen this come up on reddit again and again: the best subs are the small ones that cater to niche interests. Lemmy is essentially composed entirely of those small subreddits right now.