Idk I don't mind that the very poor that don't have phones still have an option to make phone calls. I know a lot of victims of abuse use them as a way to make phone calls that aren't monitored by their abusive partner. The homeless can use them, or maybe your phone died. I don't recall seeing ads on them but I'm not exactly looking out for payphones.

Plus I'd hardly can a phone call "ageing technology". I mean yes it's an old technology, but still very relevant especially for those that don't have other means of contact