Full-time tenure-track faculty salaries haven't really beat inflation since the late 60s. And senior profs have been substituted by adjuncts and grad students. And yet cost of college keeps soaring.

https://www.aaup.org/sites/default/files/AAUP-2021-SurveyTab...

Baumol's cost disease theory makes sense in general. But empirically, for a specific service, there's always a lot of other stuff going on, are they providing a superior good with rising demand as society gets richer, how easy is it to substitute lower quality adjuncts, etc.