Probably dependent on age of kids. For the 4yo-6yo demographic with no access to an iPhone or screen device, the analog phone is a blast. And family/friends, especially those living elsewhere, are having fun with it. Admittedly, we’re a month in but I’d be surprised if interest zeroed any time soon.
Run your own Asterisk server with special #0 that the kids can dial to listen to children’s podcasts, etc., it can be very entertaining.