They already do...
A lot of known crawlers will get a crawler-optimized version of the page
Do they? AFAIK Google forbids that, and they’ll occasionally test that you aren’t doing it.
I haven't checked in a while but I know for a fact that Amazon does or did it
With google covering only 3% I wonder how much people still care and if they should. Funny: I own and know sites that are by far the best resource on the topic but shouldn't have so many links google says. It's like I ask you for a page about cuban chains then you say you don't have it because they had to many links. Or your greengrocer suddenly doesn't have apples because his supplier now offers more than 5 different kinds so he will never buy there again.