The idiocy of the non-technical

[Wage Slave]

You can't have a universal socket for everything.

Again I confess my own ignorance here but the truth of this statement is not obvious to me. I can see that designing a universal socket may not be easy and it may be quite expensive and bulky to implement but why can't it done safely?

Obviously, it wouldn't have any role in normal domestic premises but in hotels, airports, certain coffee shops and such it would be a boon wouldn't it?

Voltage and frequency are of course another problem but power supplies for portable devices are almost invariably SMPS.