Why would you need onboard mobile? It’s 2 clicks to trigger a mobile hotspot from your iPhone and there are very cheap LTE dongles on eBay. Not sure how much service would cost, most of us have reasonable download caps on our mobile plans. The dongles have better data plans than phones.
Why wouldn’t I want onboard cellular connection instead of having to be dependent on the more finicky and less reliable Hotspot connection, hurting my ability to use my phone freely, and burning both my laptop and my phone’s batteries at the same time.
Besides, having a cellular modem also allows you to tap into both WiFi and Cellular seamlessly like your phone does to make your overall connection much more reliable.
Convenience, security, and power-savings. I currently also use a Thinkpad X13s with onboard 5G and it's nice to not have to screw with it when you want connectivity.
On my Verizon plan (Unlimited Ultimate), I qualify for two 'connected devices' to be discounted. My Thinkpad is $10/mo extra on my account for unlimited LTE. I'm not a heavy data user by any means and this works out well for me.
