On top of that, in many areas in the US the time between moving to ten-digit dialing and the time of cell phones becoming even somewhat popular is really only a few years or less. Some places in the US are only finally being forced to move to ten digit dialing with some places still supporting seven digit dialing.
https://www.kcbd.com/2021/10/12/new-10-digit-dialing-procedu...
Note the date on this: Oct 2021!
> Starting on Monday, October 25, 2021, Texans with phone numbers in the 254, 361, 409, 806, 830, 915 and 940 area codes must dial 10-digits (area code + telephone number) for all local calls.
