This is massively true IMO. Taking detailed notes during a lecture is an absurd waste of attention - we have universally-available recording technologies. Use them.
Use lecture time to do things you can't do with a recording: interact.
(Yes I'm thoroughly aware that student interaction is a myth and it pretty much never happens - I've zoned out in classes with attendance scores too. Except for several classes that many people can remember where it does happen, those don't count and there's surely nothing special about them that is worth learning from)
Shocker, that. Multitasking worsening performance? Surely that can't be a super-well-demonstrated-repeatedly phenomenon.
There simply isn't any pedagogical justification for withholding information post-lecture that was deemed important enough to be included in a lecture. Everyone knows this material is critical to understanding the course. If professors want simple optimisations to help students learn then they would be doing something like organising lecture material to promote spaced repetition.
You need to have time to process, but when you have to take notes there is a speed at which you just skip processing and instead all of your focus is in transcribing as efficiently as you can. I imagine, the speed differs from person to person. For the most of this course, the teacher hit this speed. And she knew she would hit it. So it seems universal.
If current student generation is worse at taking notes by hand, it could be a real disadvantage for them
Technical subjects achieve this with labs, too. It doesn't scale but we see clearly that scaling isn't always very desirable, especially if it leads to this regression.
You can follow along and keep 2-3 slides open at a time to have a better sense of the context, skip back to review an idea, screenshot and get clarification with AI, there are so many possibilities which enhance the lecture.
Some professors also write/diagram right on top of the slides and then provide them after class.
A lot of CS classes have switched to GitHub, with basically entirely open course materials.
Even on closed systems like Canvas, it's typically an entire library of content that you have access to.
I personally love lectures, but I'm also not doing a typical degree program, where I'd be forced to take 3-5 courses per semester. If I was under that much workload, I can't imagine having the time to absorb all the material, do all the work, sleep, and go to every lecture.
I understand that a professor may dream of lectures passing through students' brains before being recorded in high-quality, personalized notes. The reality is that lectures are easier to follow when you aren't frantically trying to copy down the lecture slides as well as what the instructor is saying (after all, it might be on the exam!)
Presentation slides are valuable instructional materials, and withholding them is unlikely to improve learning. In my experience, the best lecture-based courses (in science/math/engineering at least) provide material in at least three ways: in the textbook or readings, in the spoken lectures, and in presentation slides or provided lecture notes – with reinforcement and active learning via problem sets, labs, and/or projects. Interactive review sessions, discussion sections, and tutorials can also help.