I have the 16" M1 Pro MacBook Pro and regularly run it from a small 30W USB-C PD charger. That keeps up with the demand even running Photoshop, Minecraft, Xcode, etc.
I had one of the last intel mbas and whatever charger they shipped with that computer was downright anemic. 29W maybe then if that's what yours was? I put the computer under load with a game and the charge actually was trickling down with the thing plugged in and the cpu throttling.