Right but it's not like a 4 way stop is going to perform better. In the same case you'd expect it to be a 2 way stop.
Which is what it was for the first 70yr... And what most of them in this particular neighborhood still are, with a 0-6mo intermission.
A 4 way stop does perform better than a roundabout given highly disparate traffic volumes, because roundabouts suffer from resource starvation in that scenario, but 4 way stops are starvation-free.
But those options are a lot more expensive and need a lot more maintenance than just a regular roundabout or four way stop.
> you can also provide a "turn right" lane that bypasses the roundabout entirely.
How would that work? Consider a 4-way roundabout, where there's a constant flow of cars from west to east, and one car from the south that wants to go north but can't because of the starvation problem. None of the involved cars would want to use a "turn right" lane.