Well I was responding to a claim that it would ruin all traffic, including the people that switched. It's not my job to defend against an entirely different argument.

And this kind of thing needs more numbers in general. Maybe in a large mix of traffic, outside the edge case of a saturated link with two streams, it doesn't dominate too badly. Maybe because TCP incorrectly blocks so often, the average 'victim' user still benefits overall because only some of their devices are unpatched.

Or maybe you shouldn't really be discussing actually deploying things that harm users of the most widely used protocol out there, but instead change the new thing to deal with the world that it lives in .

The existing congestion control algorithms have flaws that make them slow down far too much in certain situations. I don't know if it's possible to make something that doesn't have those flaws and never outcompetes them. We can probably do better than BBR, but I don't know if we can do a perfect job.

You analogy doesn't work, because there is nothing pedestrians can do to counter cars driving on the sidewalk. But there is a counter to TCP BBR--adopting TCP BBR yourself.