As an average person, I've observed that both my childhood and current neighborhoods (Mid-Atlantic and Midwest respectively) have increased in the number of cars present, and that's within and between neighborhoods. I have also observed more in-fill subdivisions between neighborhoods. Since the '90s, I've seen just the bike ride that I'd take multiple times a week in my Mid-Atlantic suburb yield one acre lots turned into 8 homes, a small office park being converted into multiple 5-over-1s, a country club being turned into 400 homes. In the past decade in the Midwest, I've seen 2 single family homes torn down to make 8 units with an 8 car garage and 8 more spaces out back, multiple small businesses torn down to make way for "luxury" student housing with a parking spot for every bed room, a shopping center and apartment complex torn down and turned into an even bigger apartment complex with parking for every bedroom. Many of these are on my block or on the bike path around town.

There are more cars. There is more density.

So there you go, I've provided census data, I've provided observations from my own life across multiple geographies that backs up the data.

If you're claiming that there aren't more cars in neighborhoods, please back up that claim.