I need very little infrastructure to get around on my bike. I can ride on dirt tracks or grass, I can carry it up and down steps, I can weave through alleys or traffic jams. It needs no fuel and I mostly maintain it myself. Car centric cities often have no meaningful bike infrastructure and yet cycling is still viable. It is the cheapest, most free, most egalitarian mode of transport.

Is is pleasant without infrastructure? Is it safe? No, dedicated cycle lanes are very important.