First, the Bicycle Exchange in Harvard Square (closed mid 80s?) and now Harris.
LBS here has reduced his hours of operation to 3 days a week, and is surviving on mostly service since he cannot get new bikes in. He did pick up the local contract from the city to maintain the fleet of rental e-bikes available on the rail trail, and quite frankly, that is what is keeping him going for now. I try to use him as often as possible vs. shopping online, but if he doesn't have it in stock, even he will tell me to look online, because his chances of getting in a parts order is slim to none.