I agree it’s highly unlikely. However, I’ve been rear-ended once, and my car got pushed forward the space of at least another car and a half, in spite of my panicked reflex of pressing the brakes as it happened. I didn’t crash into anything because I was first on the lane, I got pushed into the intersection.

So yes, you can get rear-ended and the gap in front of you will save you in money and insurance claims bs time if you don’t hit anyone in front as well as a result. It will make little difference regarding your ability to switch lanes though.

In saying that, I don’t leave this massive space in front of me. I stick to the “see the next car’s tyres” rule and if traffic is really packed (as during rush hour, when everyone crawls start stop) I sometimes reduce it to curb parking distance.