Speaking from my own personal perspective, it's quite frankly scary how many teams and companies are running with skeleton crews because they've chased off a lot of competent engineers and think they can coast by with the bare minimum. Stuff like what happened to Boeing or Crowdstrike are great examples of the end result, and a lot more companies than you'd expect are operating right on the critical failure margins. The concept of redundancy has outright vanished.
Quality inertia is what's preventing stuff from crashing down instantly, but it'll eventually be the case. It's just a matter of when the last guy that's worth their role leaves.
Most "SDEs" attracted by past big money have below-minimum reading skills, can't write code, can't troubleshoot, can't debug anything even if they life depends on it. They were hired to form a particular structure for the manager two levels above to be promoted.
When Elon fired everyone, people said Twitter would collapse, but they’ve been technologically ok. They may be struggling on the business end but that’s more likely to be caused by the owner telling advertisers to fuck themselves and by him tweeting racist conspiracy theory stuff rather than any problems with their infra.