I live in one of these cities (Denver) and in my city’s case this push is part of a ton of other provisions including a push to set a maximum speed limit citywide of 25 mph.
About 80% of my trips out of the house are walking or on a bike, but it seems clear to me that policies like this don’t improve safety. It’s just lazy policy making. For example, if you set a 25 mph speed limit on a road designed to support 45 mph traffic, most drivers will still drive 45+ mph and you instead get a wild mismatch of driving speeds. This just slows traffic with an arguably negative benefit to safety. Similarly, if you ban turn on red in the city many drivers will still turn on red, but now whether or not a car will turn on red becomes unpredictable.
What our cities need is more dedicated bike and pedestrian infrastructure that is separated altogether from the roads, as well as greatly improved public transit.