"I found that there is no app that allows me to quickly mix together text, math formulas, images, sketches, graphs, and other kinds of media"
OneNote - with add-ins
OneNote - with add-ins
But it is not always quick. If you're using a pen and/or the tablet version of outlook, there are some cumbersome menus to navigate. Still not quicker than paper.
EDIT: Though after a reread of the original post, it is faster than LaTex.