The author is also the creator of the textual Python library for creating TUIs. The performance benefits of Rust don't seem very useful in a tool where you spend a few seconds typing in a prompt and then 90% of your time is spent waiting. As long as the UI is responsive when typing there wouldn't be much of a difference.
Didn’t know that. Good reason then of course. But I do notice these sort of differences. Codex feels way better than Claude code to me for example.
I tried Toad and to me it feels ridiculously slow and laggy. Switching between input and output (ALT+up/down) for example just lags, I can notice the transition. The whole UI lags. It's no wonder, it's python. Simply the wrong language for this, sorry.