Are they though? I didn't submit posts on reddit. Looking at the front page of lemmy it's missing a lot of the topics and subjects reddit posts about.

I'm not trying to be a downer, I think 250k is great and it's enough to make lemmy 100% replace reddit for me. But I don't think it dents reddit. I talked to my friends and they barely noticed anything except the blackout. I go on reddit all the same communities are still posting and commenting as normal. But saying that when I looked at reddit I realized how much garbage is posted there compared to lemmy.