This appears to be an ORGANIZATION-WIDE score. Not on individual employees.

Look at the documentation here: https://docs.microsoft.com/en-gb/microsoft-365/admin/product...

It's true that the fact they have this data means they could one day offer it per-employee. But they're not doing that today, probably because they know that the data at that level wouldn't be useful (but would be abuseful). You'd want to measure different metrics to monitor individual productivity vs organizational.