Plenty of redditors are here, reddit did originally start with a good crowd. I myself moved during the great fuckery of 2023. However i believe that a lot of the low-effort redditors (or however you would describe them) you are reffing to would find lemmy just that extra step too difficult/inconvenient to get into and wont take it up.
I don't understand this sentiment. Don't you want Lemmy to grow and overtake the big platforms? If there's specific people or instances you don't like, you could block them. I see no reason to gatekeep Lemmy. I say this as an ex-redditer.