> They lost experienced employees who were able to wrangle the bad scheduling software.

Employees could quit because they don't want to get vaccinated, but they also could have like just died from COVID too, or won the lottery, etc.

So to me this still points to the technology as something of a root cause. Your tech is as brittle as the number of people who know how to use it. Losing the people who make your sunk-cost old tech actually work, and not planning for the "bus factor' still makes it your fault for not addressing.