There wasn't much foresight required on his part because companies were already doing things like this way back when. As a trivial example, patents on DRM predate the oft-cited "Right To Read" by a decade or more. Stallman just observed these trends and took an opposing stance without (to GP's point) really addressing the economic incentives and nuances involved.
Maybe his biggest contribution is that his extreme stance and ensuing visibility probably helped shift the Overton window.
Current big tech is based on Stallman-inspired people using their free time to make software. But they are putting MIT lisence because ”someone” had convinced them that GPL is not really free and not socially acceptable!
The "things that got him cancelled" were things he said (as opposed to things he did) and those that I've read were correct (though I'm aware I havent read everything he said on the subject).
To be clear: this does not diminish his contributions in the field of software! His ideas about Free Software have been visionary and are as important as ever. One can be brilliant in one field and a fool in another. This is actually very common among technical people ("engineer's disease"). We cannot expect someone to be right 100% of the time.
