The first google result for "upnp adoption" is from 2012. The second is from 2022 and recommends you turn it off for security reasons.

EDIT: I agree we definitely need something like UPnP, or maybe even UPnP itself, but it's another adoption problem currently.

UPnP needs management. I'd like to be able to set rules about what ports can be opened by UPnP, from where, by whom, with or without a notification in email/logs/alerts etc.

Pretty much every consumer router has UPnP enabled by default.