I don't work in tech industry but from my experience it's a lot simpler than that. Most of these day-to-day desk workers know nothing but excel because that's all they know from home and work.
More subtly, Excel has a low lifetime cost because there are many good learning resources (and also many bad ones) and those resources are widely available. Which makes me think that one of the killer features of Excel is all the technical headroom it provides for solving problems...by which I mean there is usually functionality and features that could make an ordinary job faster...particularly repetitive ordinary jobs of the sort most people wind up doing.