I assume the point is that by requiring a phone number it’s a drop-in replacement for WhatsApp. There’s no need to register an account, just install a different app and you’re good to go.

It’s not the biggest barrier, but for some people it is one.

Just watched this yesterday: https://tilvids.com/videos/watch/dd5a790b-2d08-40b5-b4d0-f35ae3a68bd5

You could consider something from the Radxa Rock 5 series.

Pangolin might be interesting for you.

Gardiner Bryant did a video on this: https://video.4d2.org/w/rPMMDnLBA4kVmScBD6w9K5

The difference is, there are now tariffs: https://mamot.fr/@pluralistic/115819402267996681

There’s also a recording of his talk, it’s quite good IMO.

What’s the use case? I haven’t had an optical drive for all least 10 years and can’t say that I’ve missed it. Not even once, I think.