sorry I'm late to the party! for 'source' files you don't (often) want jpg, though it can work - we often like to use lossless compression and even higher bitdepth for image sources, increasing storage requirements even further! though it depends a lot on the nature of the particular project, I can see 'optimizing' projects for ease of sharing / hosting rather than quality as such. Other source files include blend (3d models/animation), raw data from cameras, svg, etc.

Git-LFS might be part of the solution, but it's not the solution on it's own. There are some specific problems related to work on animation/film projects that might be good to target before looking for a specific technology to use - another lil' issue is that artists tend to be much less tolerant of technical/command based interfaces, and we want to have a lower barrier of entry for them.