It still takes time and money to record videos or collect assignments and ensure legal compliance, privacy, accessibility, etc. which often utilizes student lab

It still takes time and money to record videos or collect assignments and ensure legal compliance, privacy, accessibility, etc. which often utilizes student labor, where there's an opportunity cost. That is, students, professors, and everyone in-between could be frying bigger fish. If a course is teaching computer architecture and switches from a hypothetical instruction set to RISC-V, the core of the instruction hasn't changed---memory layout, instruction ordering, digital system concepts. (The nice thing, Silvina Hanono Wachman uploads a privately recorded version of each semester of the computer architecture class, so we get the classic Chris Terman instruction as well as the modern variant.) With that in mind, some classes will have a higher relevance churn rate than others and should be updated more often. Other classes might have historically had an amazing instructor and no major development and thus need a really compelling reason to be replaced. (MIT's Introductory Physics comes to mind.)