Maybe I’m drawing conclusions about what these beacons would do, but if any of the things you mentioned stop working, I can still drive and won’t go full speed into a wall. I don’t have the same confidence in these beacons.
Does it matter? If investing in smart infrastructure is what it takes to recognize this reality, who is this a downside for? It's like saying we can't build any more intersections because we'd have to buy traffic lights.
I don't see how "helping beacons" for robots are unfair but street lights are not.