commenting to say this was a beautiful, straight to the point landing page. We see lots of landing pages with sections of copy that just don't look great
Likely there's something I'm missing, here.
Those videos or GIFs or whatever they are work fine in Chrome and Safari, so it turned out that I was missing something. :)
Perhaps you have autoplay blocked? They are set to autoplay by the looks of things.
Relatedly, I've never understood why some books have 4 pages of testimonials in the front. Once you get past 5 of these are you really more likely to buy the book?