Can't speak to Germany, but one thing I like in the Netherlands is that if you approach an empty intersection the light will automatically turn green for you. Have never seen anything like that in North America.
And the roads themselves are good in NL (huge contrast when I moved to Montreal, where we'd have a metal mesh underneath bridges to catch falling concrete)
According to Claude, NL only has 5500-6000 signaled intersections and of those approximately 900-1450 are of the type you are suggesting (iVRI). The benefit is also higher in NL due to the density and amount of cyclists. iVRI is also not latency sensitive and so installation costs are low as signaling can traverse the regular cellular network.
In the US, we have many more lights due to the road layout (grid). There are more than 3200 signaled intersections in my county in California alone despite being 1/14th of the land area of the NL.
The robot also estimates that there are 300,000 signaled intersections in the US. We honestly don't know how many there are because they are all operated by different agencies.
For US arterial roads iVRI has limited benefit. So the focus in the US has been on V2X development which focuses more on crash avoidance and has much higher installation costs due to latency requirements. In the end there's a lot of low hanging fruit here in the US if signals could just be retimed.
https://transportationops.org/publications/2012-national-tra...
NL has one procurement entity. In the US there is no single coordinating entity to standardize traffic lights. Each state standardizes its own lights and then each municipality handles its own procurement.