The issue with this is usually that you can't have power from the powerbank going into the only USB-C socket on the phone while the display signal comes out on the same cable. I think it's technically doable, but not usually with dongles that would fit in your pocket.

All the AR glasses vendors have a pocketable dongle for this.

I meant for a pocketable setup as parent explained. You wear the glasses in a coffeeshop connected to your mobile phone (the single USB-C port).

Based on some quick testing this consumes about 1% per minute on my S24 Ultra which makes this scenario unrealistic (at least for me)