I read an interesting article about COVID-19 and its impact on the supply chain in many industries.
Key point -- for the last forty years or so, manufacturing has followed the "just in time" philosophy of keeping minimal inventory of raw materials and components on hand and relied on quick shipments from suppliers. That's now coming back to bite manufacturers in the butt. The article gave several examples where companies cannot get simple things (one example was a tent manufacturer who couldn't get Velcro and thus their entire manufacturing line was disrupted.)
Complicating this is that most manufacturers no longer have warehousing space because they relied on shippers to get their components to them as they were needed. Now, companies are having to not only interrupt their manufacturing lines while they wait for parts, but they don't have any warehouse space to store the parts they can get (and of course they are now ordering more parts than what they need immediately, because they are uncertain if the parts will be available in the future). Warehouse space can't be added overnight and companies are in bidding wars to secure pre-existing space.
We've read about things like chip shortages, but we never think about all the other components that go into cameras and lenses that can hold things up, something as simple as securing the right screws to assemble a lens, rubber gaskets for weather sealing, Styrofoam pellets needed to make packaging etc. etc.
There is human nature and as
@kaihp correctly points out, there are boom/bust cycles in supply chain. In the .com boom/bust cycle of the late 90's, it was exactly the same except now we expect next day delivery.
The human nature is to stockpile when you can't get enough. This is ludicrous when you think about it as it causes problems for everyone else. The real issue was the forecasting when covid hit. Everyone thought that demand would fall through the floor and cut their forecasts and suppliers scaled back manufacturing appropriately. People lost jobs etc.
When the consumer demand actually increased there was the triple whammy of trying to restart manufacturing with less staff, [hysical capacity issues across the board and scarcity forecasting with unrealistic orders for the medium term.
Just-in-time works and has resulted in cost reductions that we have all enjoyed. From Toyota's kiretsu local supplier models, we now have global just-in-time with freight leadtimes needing some local inventory in warehouses. They should be actually using JIT to align forecast/allocations would be accurate rather than silly scarcity ordering.
The chip shortage is more to do with profitability. Supply chain works on putting relationship effort into the strategic components that are expensive and strategic. When there are multiple manufacturers of cheap products then they are commoditised and treated as such. These missing chips are made with older technology and there are less fabs now compared to ones for high end chips. Moving designs for these older (wider line width) to new fabs with smaller lithography isn't trivial and the new fabs are running to capacity as well.
The chip manufacturers are making good money at the moment but there has been and will be again times where there is too much supply. With both the EU and the US bringing on huge fab capacity with dedicated demand in a few years for sovereign/national security reasons, then TMSC etc will potentially have financial problems.