I don't think that detracts any from the initial point. Step one is still to initially only award licenses to competent drivers. That more can be done is (I suspect) a perpetual truth.
That is correct. However, this is also true in the US. So since neither requires retaking any tests upon renewal, Swedish drivers (assuming initial premise to be correct) will always be better than their US counterparts, on a proportional decline over time on a graph.
I agree that there might be something to do there, but it is again not invalidating the initial statement.