Bike lanes success are well measured and will often carry more people than a car lanes will.
Where? Outside of cities with very high density I don't see this being true. For medium density and less, what I've seen is that bike lanes remain empty. Bike counters basically show them to be failures, since the utilization barely increases over time or even lags population growth, while the car lanes remain fully utilized.
If cyclists aren't using them, they're not doing it to spite you. They're doing it because there's no network and 500m of bike lane doesn't take them somewhere useful or because they're badly designed and dangerous or very unpleasant due to heavy car traffic, pollution, etc.
"Urbanists" greatly exaggerate the number of cyclists. And on top of being in the vast minority, cyclists don't ride many miles per day, they are limited by the biology. So, naturally, even if every motorist had the vehicle confiscated and replaced by a bicycle, you would not see nearly as much traffic of cyclists. And in reality the vast majority of the tiny minority of cyclists also own a car and use it for most trips, only riding for exercise/fun.
/s