I have one Electon app that I wrote myself and it's pretty fast as well even though it deals with a boatload of things, and I didn't really put any special effort in to achieve that.

Both on my current laptop (which is admittedly a 10th gen i7) and my older one (8th gen i5).

Not to say that Sublime doesn't load faster. I'd almost be surprised if it doesn't. But the whole "Electron apps are slow" trope really needs to go.

Same with Spacemacs. because of the way processes are more expensive on Windows, Emacs/Spacemacs is many order of magnitude slower than it is on *nix (the other places I use it). I tolerate it as I can't live without magit and Org and other staples.

I find the crappy Slack app (another Electron app) is also slow to open, load and update. So much so, I prefer to use their web client in a browser.

Anecdotal, also, but that's two Electron apps which are sluggish on fairly recent (3 years) hardware.

Look into emacsclient.