What are some key features that Big Sur has removed?

[Nathaniel_Wu]

I'm kind of on the fence on whether to update my mac, of course there're new features I like, but what are some old features that are gonna be removed?
So I know .kext system extensions will no longer be supported, which will disable some software already, anything else?

 

[guzhogi]

I'm trialling Big Sur for work (I'm in the IT department). Drivers are an issue, especially older products like printers. I haven't played around with it yet, but I'd like to find out what else is broken.