> I remember that for Emacs specifically there were client side problems with parsing LSP JSON. I am given to understand that this is not a problem any more (s

> I remember that for Emacs specifically there were client side problems with parsing LSP JSON. I am given to understand that this is not a problem any more (since Emacs 27.1). Before that, the JSON parser was written in elisp which is a slow language (though somewhat mitigated with recent native-compilation). But now Emacs has preference to just use native bindings (jansson), and afaik this had solved most of the performance grievances raised by LSP clients.