The more you annoy drivers of cars and the less efficient you make streets for car traffic and the more you force them to not trust their surroundings, the safer the streets are for everyone.
Usually roundabouts are way better for this than excessive stoplighting. With stoplighting you run the risk of basically “the boy who cried wolf” and people becoming numb and starting to run reds.
I can't figure out how this would happen. Inside a city I'd expect even with excessive lights there'd still be plenty of cross traffic at red lights and you wouldn't start to think of them as useless and runnable. And inside or outside a city, I expect lights to be equipped with car detection so that main paths stay green whenever possible and when there's no cross traffic it's basically the same as not having a light.
Car detection is certainly not a standard feature of stoplights in the US, and they represent an ongoing expense since you have to maintain the detection loops, pay an outside vendor for software to maintain and modify stoplights, etc. A roundabout is more or less installed and done.
In theory but in London everyone is driving in a state of incandescent rage due to the non stop traffic lights and restrictions and people sometimes end up doing insane things because they've basically lost their head.
There are limits to the "deliberately piss everyone off" strategy
They’re driving at 20mph because the whole of London is a 20mph zone now. So incandescence or not, accidents are still relatively low for a major metropolis.
The more you annoy drivers of cars and the less efficient you make streets for car traffic and the more you force them to not trust their surroundings, the safer the streets are for everyone.