So the idea is that you leave the adapter plugged to the phone port at all times and then use the magnetic cable. You need one adapter per device, right?
(Sorry if questions are naive, I've never seen one of those).
Yes. I am using such adapter for many years now, every single device of mine are charged with the same cables. Headphones, keyboard, mouse, phones, portable speakers, iPad, android, simply everything. Quite convenient!
That's correct - I keep adapter plugged all the time (they are very slim) to my iphone 13 mini (but worked great even with my iphone xs) and another to airpods pro, micro-usb to my logitech mouse, and usb-c to my vape and android phone (I'm mobile dev). I just bought 2x such cables so that I have 2x lightning adapters and bought few to my family as gift so it's easy to share.
(Sorry if questions are naive, I've never seen one of those).