Same issue with motorcycle shops. Cost money to stock parts. Chains, Tires and tubes for general use you can find at a bicycle shop. Years ago one could get a Shimano part more easily than Campi. Now there is SRAM. Then what speed. If you want a specific width tire or brand slim chance. Well road tires width not so bad. Except if you have an older bike and want a 19mm tire. Any having the same conversation on Advrider. Some shops are good. They have ways of tracking lost sales for locals demand. Others don’t and rely on service. Not everyone can or wants to do there own maintenance.