[solarboii]

It's complexity is not completely unnecessary. Scale is a huge bitch.

Networking between phones, without a common base station, is hard. Harder than WI-FI, because identity is managed centrally and the frecs in use require a license to name some "simple" problems. Cellular comms are not designed to handle this kind of scenario.

There has been some work to add inter device connectivity lately, to support many interesting use cases. You can find more looking for "sidelink" or "PC5", but you will not find many phones that implement it.

It seems to be mostly focused in vehicular use cases in V2V and V2X scenarios