Stop signs are not a big part of driving in some countries. I obviously don’t know about everywhere, but in other countries I’m familiar with (Europe), most USA “stop” junctions are give way/priority/yield junctions where you don’t have to come to a complete stop, so stop-start would have no impact.

In the UK, you only get Stop signs on junctions where your view is so extremely limited that anything less than a stop or absolute dead crawl would just always be dangerous. They’re very rare. In comparison, Yield signs in the USA are comparitively rare (in my experience) and most junctions where you most yield priority are governed by Stop signs.