...because we've already got all the computing power we'll ever need? You think software developers not caring about performance is why we can't quickly simulate weather systems or protein folding or do large-scale ML?
For those kinds of hard problems, the advances seem to be coming in massively parallel computing of the kind that is advancing (the GPGPU has transformed ML, for example).
This miiiiight be just you. Even sublime text (forget vim or another cli editor) runs fine on ancient hardware.
What type of files are you editing?
> Or use entire sticks of RAM at rest.
I'd hope my text editors would use as much ram as it needs in order to give me the smoothest experience. If possible, that means storing the whole file in RAM (up to a set limit).