Backpressure is how a healthy system handles overload. When one part cannot keep up, it signals upstream to slow down, and the whole pipeline stays sound. Remove that signal and work just keeps arriving until something fails silently.
Teams need it and usually do not have it. A team with no backpressure does not push back when it is underwater. It absorbs, and absorbs, and then quietly breaks, often the best people first. Silence from a team is not capacity; it is frequently the missing signal.
The job is to build the backpressure the team will not generate on its own: a real, cheap way to say this is too much, and a habit of believing it when you hear it.