I was able to carry the onewheel on any transport, and that's nice, but it's not as convenient to lock compared to a bike. It's also too heavy to carry comfortably for more than 5 minutes. When you want to go into a supermarket for example you're in a worse position compared to a bike.

How do you handle an escooter in that situation?

I've seen the "carry handle" in action on a EUC, and it's pretty convenient for that. Held vertical takes next to no space on the ground so it's not much different than having a trolley.