I’ve been using Anker and don’t have any complaints. The model I have is PowerCore III Elite. It has two USB-A and two USB-C ports.
I don’t think there’s any concern about playing while charging. What I’ve been told is not to charge stuff while they’re in the overhead bin.
I’ve been to many airports where the all the outlets in an area are broken, plus you can’t assume the plane you get will have charging ports.