surely this can also be used to turn proprietary software into free

Nerve signals yes. I just try them side by side, usually running vim on both terminals and measuring how it feels. If you can feel difference, the latency is bad.

on my machine, noticeable. I seriously tried it, but went back because I could notice a small end-end latency, between keypress and action. But I'm also 240hz user.

I find Richard Werner's take on money one of the most grounded. He has done a lot of work to track how it moves in the pipes. He has done a lot of communication around the subject, that one can find easily. The same guy that is said to have invented QE.