My problem is really not the startup/loading time, but the regular stutters and long latency for input and commands.

I need my editor to "feel" really smooth and instant during editing. Emacs just never gives me that experience.

I think many long-time Emacs (and Jetbrains IDEs, for that matter) users just don't notice how laggy it is because they are so used to it, or are not very latency sensitive.