Why would this be the case? I would naively think that since the chips can only be made in a fab and the rest can be made basically anywhere that that wouldn't be true.
They can not be made "anywhere"; when you can't get that PMIC from the original manufacturer, good luck getting it from someone else. And replacing an IC in a QA tested, EMV verified, FCC and CE etc. certified device will often trigger you redoing all that, possibly requiring additional iterations. If there is a similar part available at all.
Take a look at a recent GPU and count the auxiliary components. All of them can cause supply chain difficulties.
Take a look at a recent GPU and count the auxiliary components. All of them can cause supply chain difficulties.