Anyone who works with suppliers knows they may fail to live up to their requirements, and then you don't have parts you need. In many cases, by the time you are aware they are not delivering, it may be too late to replace the vendor. Things like tooling requirements and a new vendors prior commitments means you can get stuck, because waiting on the delay is faster than firing the vendor. Consumerism works like an efficient machine, as long as no part of the process breaks down.
Just look at all the chaos Covid has caused. So many consumer products have become scarce or unavailable. ALL companies have the responsibilities you listed, but there you have it. Sometimes things are just beyond the control of the system you have in place.
At my company right now, we are over a year behind schedule on a product development, and now every company up the totem pole is waiting. But if they drop us, they have to start all over with a new company, so they are patiently waiting.