Apologies if the idea is absurd, but wouldn't a Linux handheld without a cell modem be easier to build and distribute? Think something of an analogue to iPod Touches, which were iPhones sans the the phone part.
This would skip a lot of the regulatory red tape, bring down costs, and make the devices more accessible so they’re in more developers’ hands. They’d have to tether from your primary phone which isn’t ideal, but workable.
I use a Nokia/HMD KaiOS phone as a 4G/Wifi router for the communications part of your idea.
Did you choose a KaiOS phone specifically because other current non-smart phones lack support for Bluetooth tethering (a.k.a. PAN profile)?
As far as I can tell, all currently available models from all manufacturers are based on some Unisoc platform and offer no indication of support for this feature in their manuals. Did you happen to come across any alternatives?
I'm not very keen on KaiOS given the ubiquitous advertising baked into it (which is apparently their business model).
I don't really use Bluetooth, it can pair with my car to do hands free calling but have never used that.
Got it because it was a small, low-cost, dual-sim phone that could also act as a router. It replaced an even lower cost Nokia feature phone.
Don't run apps often enough to be bothered by any advertising.
The main question, current smartphones are nearly 100% camera-phones, and people just used to camera-phone world and don't want anything else.
But unfortunately, tiny camera is hardest thing and it is not coincidence, that nearly all whales of smartphone industry regularly show outstanding camera on their presentations.
Other things except camera are mostly accessible for Linux community.
What about all these raspberry pi hats with cell modems? Are they missing anything like usable IMEI numbers or proprietary stuff? What's stopping an RPi compute module 3G/4G/5G DIY linux phone?
Battery life is probably awful, mainly.
The battery life would suck? It's not about whether you can build a phone, it's about whether you can build a decent phone.
Like Chinese emulator handhelds?
I agree, I don't really need cell service when there is so much wifi. Even would just carry a basic phone for making calls/txts even when needed.
Librem 5 already exists, so there's no need to develop a handheld without a modem.
Maybe carrying a hotspot modem with a sim card is enough?