Some accounts are deleting their posts after a few downvotes. It’s devastating on communities like c/asklemmy.
Lemmy doesn’t track an account’s karma like reddit. So, all downvotes will be isolated to your post or comment and won’t affect your account—unless you wrote something truly horrible.
Remember lemmy is a community effort. Deleting a post also removes all comments on it. So you are not only robbing the effort others put in, you are actively removing knowledge from the fediverse. Others won’t be able to find it through search and lemmy will seem lonelier than it already is.
A few times I’ve posted a reply in reddit and gotten downvoted hard. Then I post the EXACT same comment to the same post a 2nd time as an experiment. It gets upvoted hard. I have to guess that it is a monkey mind response, people do what they see other people do automatically. They see the mob throwing rocks so they figure they should toss a rock. I also wonder if people who respond to a post earlier are more likely to downvote than people coming in later.