[selfhoster11]

Legacy (style) devices are missing one killer app category: data-based messengers. Without a fully-featured version of WhatsApp, Facebook Messenger, Line or whatever it is that your friends and family use, you'll be limited to 1:1 chats. Group chats are an app-only feature, and you'll be excluded from those.

[flemhans]

An open Linux-based phone that could spawn Android VMs for each such closed messenger would be awesome. It wouldn't solve the underlying problem of having closed protocols to being with, but nobody would use the open phone if it doesn't do what they need right now.

In many countries you're forced to use closed apps to log in to government services, banks, and whatnot. If those could run in VMs it would also be rather nice. (Some of them actually try to detect if it's being run on a real phone or not).

[Syonyk]

KaiOS supports WhatsApp. And, at least some of them support group texting somewhat competently, though not the older ones.

But the reality is that I'm fine with a lot of my communication being computer-based now (with a keyboard). I still manage some group texts, but tend to only actually contribute if it's something critical ("Can you make this date work?") and skip a lot of the random BSing in the threads.

If your requirements are "I want everything I can do on a smartphone, but without a smartphone," you end up in an impossibility, so just find the least offensive black mirror you can and go on with it. But if you're willing to sit back and figure out what actually matters from a phone, and what's a nice-to-have, there are plenty of other options out there.