I don't know which version to start with, the max open files of macOS has been changed to 1024, which is too small to develop with LSP in Emacs. And this problem cannot be simply solved by increasing ulimit. In this reddit thread, rpluim user mentioned: Emacs uses pselect, which is limited to FD_SETSIZE file descriptors, usually 1024. I suspect you've got one of the file-watching utilities enabled in emacs, which tends to use up a lot of file descriptors.
