I remember looking trying to build something like this 6 years ago[0]. There are some interesting APIs for injecting click/keystroke events directly into Cocoa, and other APIs for reading framebuffers for apps that aren't in the foreground.
In particular there was some prior art that I found for doing it from the OpenQwaQ project, which was a GPLv2 3D virtual world project in Squeak/Smalltalk started by Alan Kay[1] back in 2011.
If I recall correctly, it worked well for native apps, but didn't work well for Chromium/Electron apps because they would use an API for grabbing the global mouse position rather than reading coordinates from events.
This reminds me of the original patents that Magic Leap had, which involved pumping light through a single optical fiber that was wiggled by piezoelectrics into a spiral to project light (https://kguttag.com/2018/01/06/magic-leap-fiber-scanning-dis...).
Another fun calculation is that due to special relativity, a hard drive that is spinning gains a certain amount of mass due to the rotational kinetic energy and E=mc^2.
Assuming the platter is 100g, 42mm, spinning at 7200RPM, there is about 25J of rotational kinetic energy, whose mass equivalent is 2.8x10^-13g (0.28 femtograms).
Assuming 200 electrons per NAND floating gate with 3bits/cell TLC on a 2TB SSD, there would be 5.3x10^14 electrons, weighing about 0.5 femtograms.
I've recently been enjoying OrbStack (https://orbstack.dev/), which I've found easier to get started with than Lima, starts up faster, and automatically mounts volumes so you can access things from Finder
So this must be why last week's updated "App Store Review Guidelines" explicitly excluded "one-to-many realtime experiences". Third party fitness apps need to fork over 30% to Apple, while they launch their own first party competitor.
3.1.3(d) Person-to-Person Experiences: If your app enables the purchase of realtime person-to-person experiences between two individuals (for example tutoring students, medical consultations, real estate tours, or fitness training), you may use purchase methods other than in-app purchase to collect those payments. One-to-few and one-to-many realtime experiences must use in-app purchase.