Yes, going to bumfuck nowhere will be more efficient by paving 800 miles of concrete, but by definition most people are in urban centers, and there's no reason you can't have cities that are human-friendly while still having cars as options for the people that need it. In the Netherlands, ~65% of people still have cars and take their cars for long journeys, it's just that we have alternative options to get around so the people who can't or don't want to have a car can choose to do so without being crippled in their mobility.
What's the excuse with cities like Oulu in Finland, which isn't flat and is covered in snow more often than it is dry? Despite those 2 potentially huge issues, they still have incredible cycling infrastructure. Or Switzerland, where in my experience in at least Geneva and Bern the cycling infrastructure was also superb despite the mountainous terrain? No one's saying you need a cross-country bicycle highway, as long as the dense urban centers have good bike infrastructure it's more than enough.
Also I didn't even mention bikes in the comment you were replying to, I was talking about public transport like trains, trams and buses. Again, Switzerland despite being extremely mountainous has a world-class rail system that literally cuts through massive mountains.