It’s all about the heat. It’s not dumping 120w non stop even over 90% for example. OnePlus also use supervooc not standard usb pd. My phone legit does 150w max and while I mostly use my 80w charger because my tablet uses that I can’t say my battery seems affected much 2,5 years in.

A little more info on it https://www.androidauthority.com/supervooc-fast-charging-686000/

Just one more lane, bro!

If that… I imagine they were white label products so not even those taught him anything