I agree with you that a graphical interface works better. All existing sheet music follow this same format. It seems strange that some are trying to go in a vastly different text based approach.
sponsorblock doesn't just have sponsor segments. There are segments for intro, outros, filler content, non music section for music videos, etc. Depending on the type of content you watch, skipping these segments are great. Sponsorblock has a config option so you can toggle on/off which type of segments you want to skip.
Markdown and html can display local images. The only tricky thing is if you want to place images in separate folders and how you maintain that structure over time.
I believe that charts and diagrams convey a lot of information that cannot be easily reproduced with raw text. I guess it ultimately depends on the topic you are reviewing.
If I search the intro to robotics course online, I see there is a playlist from Stanford but the videos are 14 years old. Does anyone know if there are more recent videos? Or are there other courses that are good for robotics?