I just use a battery pack as a go between -- I never plug my phone directly into a public charger, I either use a tiny charge cube and plug into the wall (if I can find an outlet), or recharge a battery pack that I use to charge my phone.

Another advantage of the battery pack is that I'm a lot less worried about leaving a $15 battery pack unattended while I go pick up some food than my $500 phone.

Yes, I keep exactly that kind of short cable in my travel bag. There are also USB-A versions for the more common kind of port you might find.

https://www.amazon.com/dp/B082WDHS22/ref=vp_d_cpf-substitute...

USB-C has meant that cables have split into one paradigm with high power draw and low data transfer speed (for charging), and a separate paradigm with low power draw and high data transfer speed (for data transfer). You need to buy separate cables and then keep track of which is which, but, luckily for you, they have exactly the same connectors. It is not clear to me why this represents a technological advance over the ancient system of having separate power and data cables using different connectors.

On the other hand, you don't see power cables with no data transfer capabilities. For phones, the obvious solution would appear to be the fact that when you plug your phone into a power source that also has data capabilities, it defaults to "USB is for power only", and you'd have to manually switch it to data transfer if you actually wanted data transfer.

For laptops... how often do USB-C-charging laptops accept data through the charging port?

There appear to be numerous choices on Amazon, both cables and dongles that work with your existing cables.

Of course, that depends on the data blocker itself not being compromised. :-)

Exactly my thought as well: aren't data and power pins on all USB standards separate anyway? Just buy a charge only cable.