The problem with being on-call isn't that you're working, the problem with being on-call is that you aren't not working. You can't be on-call and go to a place

The problem with being on-call isn't that you're working, the problem with being on-call is that you aren't not working. You can't be on-call and go to a place you're not allowed to have your cell phone on. You can't be on-call and drink alcohol. (or other substances of various legalities) You can't be on-call and go camping in a wilderness location that may not have cell coverage. Depending on the circumstances, you may need to lug your work laptop around in your backpack.