The lecture format has only been competing with high-production-values video for a decade or two, and with interactive examples for much less than that.

Interactive examples using Macromedia Flash or Java applets are straight in the "a decade or two" time frame.

(The 3B1B one is of course also among the best :

https://eater.net/quaternions )

And, while it was before my time, universities might have had some before the World Wide Web ?

Video has been around for much longer than that too.

I'm also not sure why "high production values" is supposed to matter, aren't Feynman's video lectures good enough for you ?

The vast majority of students never ask, “what if…” The vast majority just want to know the mechanics of doing the problems well enough to pass the test. At the time a student is taking Calculus 1 they don’t ask questions about why it works. They just want to know, for instance, the rules of differentiation. Later in life, when they have intellectually matured, videos like 3Blue1Brown are interesting and fascinating. The vast majority of students would not learn well from 3Blue1Brown type videos.

Those students will not learn no matter what form of pedagogy you use. But 3blue1brown lectures are great for those who do want to learn

Yes. But in the classroom most students don’t want to learn. Hence my statement that it wouldn’t work in the classroom.

The goal of education is to educate that unvast minority and for them to become deeper specialists faster.

To hell with the majority which will forget it next week and go management or delivery. They are unimportant for the key idea of education.