Always been disappointed that nowhere went with arbitrary length numbers for phone numbers, with the excess/end forwarded on to wherever the prefix is. I suppose that's not possible with the amount of time needed to actually do the switching, and would tie up a lot of switches before a call ever connects.
Or, assuming every number ends with many 0s that are omitted when dialling. Mainly to make extending the numbers easier, though you would lose 10% of the available ones.
It is technically possible to use a pound key (#) as an end of input indicator. It is almost impossible to change the users habits though, not mentioning the need to reprogram thousands of telephony switches. Another (better) option here is packet sending of DTMF string - digits are collected on a smart user's device (i.e. iphone) and the complete number is sent as a digit string, not one by one. Problem here is that there are still lots of dumb phones that don’t do that. Analog lines (copper fxo/fxs interfaces) are also present even nowadays. So as usual, legacy and backwards compatibility are holding back progress.
Or, assuming every number ends with many 0s that are omitted when dialling. Mainly to make extending the numbers easier, though you would lose 10% of the available ones.