Actually, at the recommended 2 seconds, he does. He moves into gap, the following car drops back to maintain 2 second gap. It’s hardly rocket science.
OK. And the car behind that one then moves back, and the next, and so-on I assume you mean? So the overtaker relies on all of the other cars to move away from him, rather than him just keeping away from them in the first place? That is precisely how random slowing down of traffic happens, with the wave of slowing cars causing a “thickening” of the flow.
If the space is there to move in to, fine. If you are going to try and manufacture a safe space by forcing your way in and expecting the line of cars rearwards of you to oblige, then not fine.