> It must be really really really good for the HR decision makers though

Data Integration.

Workday is extremely good at integrating various different data sources and providing support to build integrations if they are not offered by them.

A private research university like WUSTL is a conglomeration of around 10 colleges all of which all have their own internal operations, a couple organizations dedicated to facilities maintenance, an entire community medical network dedicated to STL metro, a major sports program, housing for students and faculty, procurement, insurance, etc.

All of these are entire business units or functionally independent organizations. And in this complexity arises multiple different organically developed data stores, schemas, and practices. At that kind of scale, liability grows exponentially and you as an organization need a way to better understand what is happening.

That is why products like Workday are beloved by enterprises.