Wireless spectrum is limited, and older protocols were less efficient so the same spectrum can handle more devices.

This made a massive improvement in places like subway stations, stadiums, airports, etc. where you have a ton of clients in a limited area, often all activating at the same time.

It would be interesting to know how much of the efficiency improvements were only in software – a lot of waste could be avoided if your old Subaru could speak enough 4G to be on the network even if it couldn’t do the higher data rates. Obviously improvements which are just due to clients completing their transfers wouldn’t be an option but I wonder whether any of the more efficient background activity, notification, back off, etc. logic could be backported.