In his old year cabaret show, Peter Pannekoek stated the buttons near crossings don’t actually do anything, they’re just there to just pacify people. I’m fairly certain they in fact do work, though for cyclists they’re mostly redundant: the magnetic loops in the road surface detect cyclists. Only for lightweight carbon bikes a manual button is still useful.
Am I correct in my assumption?
They absolutely do something!
If I don’t push the button, there’s a good chance that a light which looks to want to change to green, will stay red, and the flashing “don’t walk” hand will turn solid, and you’ll miss the “walk” + green.
I’ve had to wait twice as long at some crossings because of that.
Even in cases where the light turns green, if the button isn’t pressed, sometimes it will not show the “walk” symbol, even if it’s OK to do so.