Ghostty is quite slow to start on my Linux machine, very close the the first start of GNOME Terminal (or Terminator). Maybe because I'm on Wayland? Are you on X?
I had this issue a few years ago with certain applications and came to find out that it had to do specifically with them using GTK. I googled for it and found the fix, and after all the same apps started practically instantly. Could this be what you're running into?
(I haven't used ghostty so I wouldn't know whether it's actually fast to start up, but what you wrote reminded me about this particular issue.)
Yeah, I'm still on X. I'll make the switch when I haven't heard a friend get really annoyed by something Wayland related in a year or so. It's a Debian system. Not sure if it matters but there's an RTX A500 in the machine.
So, perhaps? For a while I was on a local compile of 1.0.0, and a while ago I started pulling the nightly sources and build from those.
(I haven't used ghostty so I wouldn't know whether it's actually fast to start up, but what you wrote reminded me about this particular issue.)