> The issue is that when you slow down, you’re (a) creating ‘turbulence’ in the traffic flow with increased speed differential between cars and increased lane changes, which increases accident risk for everybody, and (b) it’s not even solving the problem because you still perpetually have some impatient driver wedging themself in directly in front of you, deleting your buffer zone.

That's very obviously not true. Slowing down always reduces energy in the system and always reduces global turbulence. It's one of the reasons that countries that lower speed limits see journey times reduce.