Sometimes there a track record of output to reference on. Project velocity. There’s a lot and I probably work in industries that aren’t comparable to yours so no use getting specific. Sometimes it’s just a hard thing for ICs to look at the whole operation instead of their part. The fact ICs think productivity is the most important thing they can provide is a signal they’re wrong (in the eyes of a leadership team).
The management team doesn't want it to be up for discussion, and doesn’t want to create wfh subclasses of employees, which is what data would lead to.