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.
I appreciate that this is an open source community where speech is more flexible which is what I was drawn to about lemmy but as with before I got banned on reddit, if I feel if my posts are embarrassing or show that they have no value to the people I am talking to, then I will remove them to not clog thread space.