Isn't the same as being sat next to them and being able to lean over or just ask though is it? You can keep your code on your own screen and just nod in.
leaning over is just as much a context switch. “just being asked” something is often a rude interruption of concentration.
over chat i have the opportunity to take a minute to wrap up what i’m doing. I also walk away with a written record, so if ive asked for help, i have reference to go back to. which can then serve as a starting point for documentation. or others in the chat can read and passively absorb information. or contribute to the conversation.
The screen context switching is a killer.