Like most of us I have multiple chargers from the days when Apple devices used to include a charger. The little cubes and the larger iPad chargers have USB A sockets and USB A to USB A cables. I know I can buy cables that are USB A to USB C to allow me to use the old chargers with a new cable to charge the new wave of USB C devices both iPhones and iPads. I’m not concerned about speed or magsafe. My question then is this, is there any reason not to buy such a cable and use the old chargers on new iPhones and iPads?
If you don’t care about charging speed, that’s a perfectly fine thing to do.
In fact, slow charging is the battery-friendliest way to charge your iPhone. Especially for those of us who charge our iPhones over night while we sleep and don’t care if the charge takes 5 hrs, even Apple’s small old 5W USB-A charger will do the job just fine.
A-to-A cables are non-standard and were rarely used except for some very special-purpose cables.
Apple’s charger bricks, depending on generation, shipped with one of:
USB-A to 30-pin Dock (the oldest iPhones, iPads and iPods)
USB-A to Lightning (more recent iPhones, iPads and iPods)
Nothing (most recently)
They could be used with most non-Apple devices using a USB-A to micro-B connector (commonly found on all non-Apple phones until they switched to USB-C.)
Not counting the earliest iPod chargers, which have FireWire connectors. Which would include either a FW-to-FW cable (for the first-generation iPod) or FW-to-30-pin Dock (later iPods).
None whatsoever. They will work just great. The only thing to keep in mind is that these power bricks are going to be relatively low power (mostly 5, 10 and 12W), so they won’t charge a modern device at high speed. But if you’re OK with that, go for it.