Yeah. It's slow on Linux, for sure. I use Foot, which as far as I've tested is the fastest to launch. I use Niri and launch Foot terminals all the time as part of my workflow (it's just how my mind works), so time to launch matters to me.

Monstar is a libghostty derivative that resembles foot: https://github.com/rockorager/monstar

Namely it is wayland only, cpu rendered, and doesn't have any window decorations