If you live in a place where you don't need a car, then sure, I guess that might work, but the VAST majority of Americans do not. They would have to move somewhere else. There isn't enough housing in such places, so new apartments (and schools and stores) would need to be built. That takes time and emits a bunch itself. We don't have the time to empty the suburbs (and no chance it'd happen politically). So the fastest solution BY FAR is electric cars as we can decarbonize people where they are.

A lot of cycling advocates massively underestimate just how good electric cars are. (They also last at least 10 times longer than bikes, in terms of number of miles... including tires, etc.)

People want climate change to force solutions to other problems. But we didn't solve ozone depletion by getting rid of refrigeration or air conditioning. We did it by developing and using non-ozone-depleting refrigerants. There's no political will to do much else, except around the edges.

Absolutely, build better biking infrastructure. There are good reasons to do it. But electric cars and trucks are WAY more relevant to actually getting most of America off of fossil fuels in a politically and economically feasible way than telling everyone they have to bike, now. Technological solutions are more feasible than social ones.

(Also, all the inputs to an electric car CAN be decarbonized as well.)