I used a number of terminals in the last decade and even 2 GPU accelerated ones, Kitty and Alacritty for about 2 years or so. Now I'm back on Konsole. I never saw a difference in their speed, because the terminal speed doesn't matter. Maybe there are edge cases, that's not something I discount. But for writing code or editing text files, or listing files with the shell, I never saw a difference or advancement for having a faster terminal.
However, where they differ greatly is in their customization, feature set and what dependencies they have.