It is not surprising if the goal is not to fill vacancies or expanding needs, but to prevent competing companies from having these people at their disposal. There will be enough offers to cover every possible person who could do this computer-focused work that might go to work for a competitor.

Another explanation is that there is a high attrition rate (e.g., like Amazon) and the company must overcompensate. Thus there will always be high numbers of advertisied positions that are never filled.

A third explanation is the company just has too much money and no clear ideas on how to spend it. (Case in point: Metaverse) Companies tend to sustain higher and higher levels of, for lack of a better term, "stupidity/foolishness" as the cash flow increases further and further beyond the company's immediate needs. Having heaps of cash on hand does not necessarily focus the mind; it can have the opposite effect.