It makes no sense to price wireless data based on IP transit costs.
IP transit costs per GB are a fraction of a hundredth of a penny.
It barely makes any sense to bill consumers per GB on any terrestrial network.
In Northern Europe a typical 4G SIM with a monthly data quota is $9 per month. An unlimited 4G SIM with all you can eat data is $18. How many price points do you need in between?
Heck, international 4G/5G data roaming fees are capped at $2/GB and by 2027 the cap will be $1/GB.