This makes no sense...the majority of mock ups/VI libraries for film especially get replaced by live players. Sometimes the VIs get layered in with the live performance, but look at the Black Panther score...all live percussion.
And I know many A-list composers that pay for all their libraries...only a select few may get free libraries as promotion, but certainly not all of them, and there a lot. So maybe 1-2 top composers get free libraries...not a call for concern. And on top of that, a lot of the top composers also have their own bespoke libraries from projects they've done...Junkie XL comes to mind.