Corporate research is still going to somewhat be at the whimsy of what's bleeding edge AND has some applicable value; the idea of it just is a little different with things like the 10% or 20% "constructive free-time" model. Each engineer in FAANG-like companies just get a 10-20% salary allotment instead of the equivalent expense of researcher headcount. The idea of "constructive free time" for work is just the "agile" iteration of the research lab.

Except “constructive free time” mostly isn’t a thing anymore, right?

You can still get 20% time at Google. But you have to take it. They don't shove it in your face.