Earlier quoted context omitted.
Not that barrel plugs are any better... I wish I would have wrote the model down posterity, but at one point I worked a trading company and a number of the users had ISDN at home. There were two 'different' modems, and I say different because only the model number on them notified you of it. One had a plug that output DC power. One had a plug that output AC power. They were the same size wall wart. Same size barrel.…
Barrel plugs ARE better because there is very little certainty about them so you always have to check the voltages/polarity. Because usb-a is near ubiquitously 5v over certain pins most people will plug in a usb-a into any socket they see.
Probably the best connector we've got for things that need it, but I'm glad we have USB-PD power now