The mobile infrastructure has a hefty upkeep fee, regardless of usage. Many other utilities have monthly base charges just for the connection.<p>Of course now that people have more than one device the number of &quot;lines&quot; isn&#x27;t fixed. So it does seem ridiculous that multiple devices means paying multiple upkeeps for the same infrastructure (disregarding the bandwidth used by control messages).<p>But given the glaring security issues with common cell radio chipsets, having multiple devices directly on the cell network is an antifeature! The same communication can be accomplished with a dedicated hotspot or a phone that tethers for everything else. Data is data - what is the advantage of making yourself more legible to the cell network?