JIT is seriously shitty. Perfect territory for pulling examples of how the incentives of capitalism lead to stupid, wasteful, inefficient behaviors.
I work in freight forwarding and the customer I've mainly worked with ships a lot of audio & infomedia unit components for the automotive industry. It's often completely fucking bonkers out of control stuff. We're talking insanely expensive emergency shipments happening on a daily basis to prevent factory shutdowns. I've seen some ridiculously extreme measures take place. Like proposals to fly a helicopter out to a container ship to pull out a few small boxes, attempts to stop trains, 300 kg of cargo strapped to handcarts and checked in on passenger planes as baggage by teams of couriers, planes chartered for $50k+ to save an hour or two on moving 100 kg of stuff a couple hundred miles.
It's mainly about cost-cutting pressures, and the asymmetrical leverage involved in the supply chain business contracts. Suppliers are often forced to promise delivery windows as narrow as a specific hour as condition for doing business, and if the factory shuts down because the supplier doesn't fulfill that promise, then it's the supplier who ends up contractually obligated to absorb those losses. And the blame/cost-shifting chain doesn't necessarily stop there, but you get the idea. And every step of the way is lubricated by salespeople who don't know how things really work pitching unrealistic promises to executives who don't know how things really work. So while this supply chain model is highly disruptive to their productivity and real societal utility, it's not actually much financial risk for the end-product businesses who are making the decision to use it. They're saving money. Losses are externalized to smaller fish several steps removed in the chain of business relationships.
The one valid argument I've heard for it is that automotive production cycles are so small that inventory becomes obsolete too quickly to take advantage of warehoused parts. Every make/model is re-designed every year, and only in production for a few months before everything gets re-tooled for the next iteration. So given that, it's internally logical to avoid keeping extra parts on hand that will go obsolete and have to be liquidated so soon. To micromanage exact quantities on tight schedules instead. But the broader view is that it's just another layer of insanity that there's so much pressure to iterate so quickly and cause so much waste. We could materially do so much better by slowing down and maybe making larger leaps less often, involving people with operational knowledge in decision making, and approaching business relationships more cooperatively. But that approach isn't geared towards quarterly number drives.