Something i notice when working on projects that are preset, or i just continuing with, is that a lot of elearning projects lack proper image compression.
Especially with project that are build on imported Powerpoints often the images in Powerpoint are just scaled down to fit the authors need. When you do not watch that and fix it, the final images in the elearning are unneeded big. On desktops with a fast internet connection this wont be a big problem, but just imagine thats a responsive course and the same image will be used for the mobile version.
As a sample i made this lesson in which you can see the differences between the different options to compress an image.
When an image is compressed properly you will notice that immediately. It loads quicker then a not or bad compressed image.