Seconded. Sadly, our tech stack at work still includes some webforms cruft and I have a few friends at other companies that also still have to deal with them. Could be worse I guess...I know someone that still has to put up with classic ASP.
Thankfully I work with backend stuff at my job currently or I'd probably go crazy dealing with a mishmash of mvc and web forms. Webforms are not super easy to get rid of if you weren't careful on how you coupled to them, so I think some code is still being added to ours.
Even this year I was getting some SiteCore requests, which I didn't accept, but version 6 was largely built on top of forms.
I haven't bothered with it since version 6, so I don't know how well it has moved into MVC world.