If you are commuting by bicycle and literally only have one bicycle and no spare parts and no concept of the many many many many many other ways to get around, you probably are missing quite a great deal in the old brain compartment.
A bicycle commuter should have a spare bike, some important wear parts laying about (chains, cassettes, tubes, cables and housing, brake pads...) and if not the spare bike at least the knowledge that there are many ways to get to work other than the bike. They should also have some basic knowledge of basic bike care and maintenance and also should come in during slower cold seasons before everyone else. Generally pre-pandemic aside from being super busy during the spring and summer we had parts for most things could get you back out relatively quickly. Of course if you have some less common stuff or really abused your bike you could be in more trouble but that is on you for your poor choices.
The biggest problem in bicycles as transportation is infrastructure, we need better and safer ways to travel by bike and more awareness of cycle-commuting and incentives for people to ditch their cars and use bikes more often. We may not get a Dutch or similar Euro experience but we can at least make some bigger strides. Certainly things are getting better inch by inch and I am seeing more cycling lanes on the roads and other stuff to help us cyclists and some drivers are becoming a tiny bit more aware but we have a way to go.
Though yes we should blame bike shops for your inabilities. A shop cannot nor should they need to stock every single little part for every single bicycle that is probably a good billion in inventory plus space to keep it all and paying inventory people to count it and buy it. Waiting a week isn't bad I can take public transportation, walk, rent a bike, über, lift, car sharing or car rental services, drive my own car (if I had one), carpool,
slugging, rent a scooter, jog, cartwheel, taxi, other private car service, telework/commute, ride my second bike, rollerblade, rollerskate or maybe some mix of any number of these. Maybe also see if the shop is willing to let you take the bike and drop it off the night before scheduled service or when the part comes in and they can schedule you, maybe not every shop can do that but if you are a good customer or at least polite and decent about it they might let you.
Also as
Nyah said Covid-19 isn't over and we haven't seen any post-pandemic because it is still raging on. Let's not assume because we are barely at 43% of people vaccinated in the U.S. that Covid is magically over. If you got a 43% on your test in high school that would be a failing grade. Yes in terms of the virus it is better but still a failing grade.