This reddit thread¹ details thoroughly the connection to Meta (Facebook) and to a lesser extent Discord as being behind the push in the US.

1. https://old.reddit.com/r/linux/comments/1rshc1f/i_traced_2_b...

You can buy a cellular data plan for your laptop. Just plug in a 5g radio to your usb port or in some laptops you can even install it internally in a dedicated pcie slot.

Carrier approval is not the reason phones are locked down. If it were then rooting android devices wouldn’t be possible.

The marginal cost of one extra passenger is going to be very nearly zero. The vast majority of the cost is just moving the bus / train / plane, and the overhead / inefficiencies in the system. I've seen somewhere the numbers for one passenger on trains and planes but I can't remember where that was. Just know it is a very very small amount for the added weight of one more passenger.

Yes, similarly in the US: I think the largest portion of the energy in the US is produced with gas fired power plants.