Not only were films of Vonnegut’s books not very good, they weren’t commercially successful at all. They’re really not talked about. (One that I missed was an adaptation of the short story Harrison Bergeron starring Sean Astin, who appeared in it right after Rudy, but it’s not very talked about either. It’s available on Youtube, but it’s been a long time since I read Welcome To The Monkey House.)
I don’t think Vonnegut’s popularity has gone down the toilet or anything since he died, but God knows what they’re assigning in high schools these days.
I seem to recall that Richard Kelly (Donnie Darko) was planning on doing an adaptation of Cat’s Cradle which would have been called Ice Nine but that’s probably never going to happen.

Heh, a friend of mine is getting into Le Guin right now, I got him to read “The Ones Who Walk Away From Omelas.” I had to check and see if Le Guin was still alive or not (she died in 2018.)