I've been using alacritty, another new-ish GPU accelerated terminal emulator, and I can confirm that its performance is better than gnome-terminal or similar. So at least there is something to this idea.
> Alacritty is the fastest terminal emulator in existence. Using the GPU for rendering enables optimizations that simply aren't possible in other emulators.
I wonder though why people need fast terminal emulators (?) I'm using "xterm" and I haven't found any issues with speed.
One thing that I thought would justify this is that they don't support scrolling text by themselves and to have it you're required to rely on tmux or screen.
Without acceleration it's a blur.
Another approach is to run "screen", which has several advantages: (1) not all text needs to be written to the terminal, only the text when you actually look, (2) you can open the computation on a different computer later (e.g. perhaps at home to check if everything is ok), and (3) if you accidentally close the terminal the computation keeps running.
In both cases, my terminal emulator does not need to be fast, really.
My biggest issue with speed in the terminal comes from network latency (which is difficult to fix).
Oh, and while you are at it, have a look at mosh as well. Mosh bills itself as the ssh alternative for mobile, intermittent connections but it does take the idea of 'not all text needs to be written to the terminal, only the text when you actually look' even further.
Mosh also has lots of network latency hiding tricks up its sleeve.