How much surface land does public transit occupy per primary transit user? How much does pedestrian-first and bicycle-first occupy per primary walking/cyclists? Now how much land does car-first take per person primarily using car for mobility?
The last is far, far higher than the others. Depending on the city, cats get dedicated infrastructure covering 25-75% of all land! Add buildings and parks and you get scraps for everything not cars.
In a place like Manhattan, the sidewalks are wide and, like I said, plenty of space has been made, and continues to be made, for bike lanes.
The good thing is that space for pedestrians and cyclists doesn't actually require taking away that much space from cars as a percentage. There's plenty of room, you just knock out a lane, as NYC has been doing.
So I don't really know what you're arguing? It's not "table scraps". You certainly don't need the width of a 4-lane highway just for pedestrians and cyclists.
Residential streets with little traffic don't even need bike lines. But many of the busiest avenues have them.
NYC could always do better, but there's nothing "table scraps" here? It's massively improved my cycling experience. And it gets better every year.