For 99% of the population it isn't practical to use a bicycle for daily transportation. This has nothing to do with shortage of parts. I was a daily bike commuter for 14 years and I temporarily stopped daily commuting because of a job change, it had nothing to do with bike shops being unable to supply parts. I still ride for recreation but I don't use my bike for daily transportation like I used to in the past...Personally I never experienced any shortages of bike parts or components that would prevent me from riding. I have 3 bikes, 6 extra wheels and many parts which I keep at home. Every time I go to a bike shop they always have the basic essentials such as: tubes, tires, brake pads and cables, bar tape, handlebar grips and etc. I have no idea what you're talking about.