Most often the slides alone are useless, they are only supposed to be a support for the talk. Talks recordings (or transcripts) are more useful, you can only get a high level idea of what the talk is about from slides.
I would be awesome to have a platform where you get recommendations of what to learn / read or online courses in order to understand a given talk.
Yes absolutely! A platform where not only the answers are praised, but also curious questions.