I understand why you say this, but I think this is not exactly the issue. I do carry an internet-capable device, whenever I might need one (i.e. less often than you would think).

If I were to carry a smartphone for this purpose then I would get a worse experience than I do on a larger screen, and it would hinder my ability to use telephony services when I need them.

For my needs, those services do not belong in one device.