There are too many dimwits who think Lemmy was made so that they can build their echo chambers. So, there is no discourse, just stupid people encouraging stupid people. Anyone that comments otherwise is immediately removed.
Most mods are dumdums. Most are obviously politically and ideologically motivated. It's their job to prune anything they disagree with, which means they can't help themselves and ban everyone. Most of the time it's a complete waste of time to comment in smaller subs. The dumdums have taken hold either by making the subs and controlling them, or by volunteering as mods with no oversight.
Last week there was a woke-not-woke argument in certain StarTrek post that was like one quite moderate guy against 1000 angry people. At least in reddit there was some debate posible and it was respectful for the most part, here you get dilapidated before even be able to explain yourself. Lemmy is too politically driven as you said. And that's insufferable.
Six months ago lemmy was infinitely better than reddit in that regard. It's gotten worse because people from Reddit are here now, and brought their idiocy with them.