You jest, but if someone makes a decent enough full-spectrum daylight simulator, and then get a stamp of approval from FDA (or whichever the authority is relevant here), they stand to make a lot of money by enabling residential use of windowless spaces.

(Cue arguments on how dystopian this is. But hey, if the daylight simulator was to-spec, it wouldn't be the worst of things.)

There was Munger Hall [1] but they didn't actually build it thankfully.

[1] https://en.wikipedia.org/wiki/Munger_Hall

They already have fake skylights that simulate Rayleigh scattering, but the main issue of not having window access is fire safety.