The root cause of all our shortages is due to a business philosophy that I noticed was taking hold during the early years of the Clinton administration. Regardless of when, Just-In-Time capitalism is now the root cause of many of our supply woes - including shipping. Simply, JIT means manufacturing at the pace of sales, so the product hits the shelves just in time for a sale. The idea is to minimize dependence on warehouse-product storage and avoiding losses due to spoilage. Even canned goods eventually expire in a few years. JIT is easiest to implement if you control a large chunk of the market for your goods or services. Economists call this control a 'monopoly' - a term made famous by the Parker Brothers toy and game company until they were bought out by the Hasbro toy monopoly.
Oddly, monopoly eventually creates catastrophe on a tsunami scale as we saw in the USSR, and might see in China eventually. A recent metaphor is the baby-formula shortage, although it applied to past shortages, like paper towels, and face masks. JIT Central control of a supply chain creates amazing efficiencies and big profits. However, if the leaders of that monopoly make a mistake, the impact is often immediate and catastrophic.
Look at Texas' don't-tread-on-me electrical system. In 1930, it seemed like a great idea to skirt federal regulation and run the state electrical grid on a shoestring providing JIT juice to residents and businesses. However, as the state's population grew and electricity dependence grew an order of magnitude along with it, the lights went out, as well as the heat or the air conditioning (most of Texas enjoys both winter snow and brutal summer heat). JIT is likewise causing a shortage of baby formula of late because the largest producer of the stuff, Abbott Laboratories, appears to have taken one too many shortcuts, and when the FDA finally wised up, a humongous recall was triggered. Time that should have been spent keeping the factory clean enough to meet FDA standards is being lost to clean up the plant to FDA standards and start producing product again sometime in the future. Meanwhile, there are no warehouses full of baby formula, or much of anything else these days (e.g., computer chips, meant, and lumber - we are burning down wood-frame houses faster than we can rebuild them out of more wood.
I read somewhere recently, that the Biden administration was considering to study what we should be stocking up in warehouses. He might start with ammunition as the US is running out of rockets, rifles, bullets, etc., to gift to the Ukrainians. "Oh JIT," said Raytheon (or something that sounded like that). They don't even have an assembly line for Stinger missiles anymore because DOD stopped buying them. They might have some Stingers ready to go about the time Putin leaves office. Not to pick on Raytheon, the same problem ran us out of surgical gowns, surgical masks, rubber gloves, respirators, and on and on when the pandemic hit.
The pandemic is probably the most impactful of recent JIT failures because it took a million American lives - many of which might have been saved had the Trump White House not disbanded the National Security Council Directorate of Global Health Security and Biodefense. Then, instead of reconstituting it when COVID arose, he elected to ignore the pandemic for months dismissing it as nothing but the flu. Thus, the director of the public health monopoly for the USA (Trump) compounded one bad decision after another, until the entire nation was affected - and millions of Americans were INfected.
Sadly, these shortages will continue until the US either reins its monopolies or starts to regulate storage requirements of reserve products to avoid costly and potentially deadly shortages. It is not as if Congress is unaware of the problem. Senator Warren has been quite vocal about monopolies and SEC rubber-stamping more and more of them every day. So has Bernie Sanders and several others in Congress. Journalist Matt Stoller has likewise been trying to educate the public with video's TV appearances and his 2019 book "Goliath," his Substack posts and magazine articles. Alas, so far, voters seem to be merely grumbling to each other about shortages. While political parties argue whether or not schools are grooming children to be gay while encouraging schools to groom children to justify racism, male dominance, and homophobia.