I don’t know when you last tested the start-up time, but we significantly improved it in HTTPie CLI 3.0 [0]. Now it’s still slower by ~0.1s.
$ time http --version
3.2.2
real 0m0.113s
user 0m0.087s
sys 0m0.020s
$ time xh --version
xh 0.18.0
-native-tls +rustls
real 0m0.007s
user 0m0.002s
sys 0m0.002s