[grey-area]

I really disagree with you that Git is not a good tool for designers. It's certainly not friendly to learn, but for designers who get the process, it is incredibly useful. If you have lots of 900MB binary blobs I guess that's going to be a problem, but the vast majority of assets in a website or app are text files, jpg and png files which are small, and the vector artwork or PSDs used to generate them (for vector that's really small, for psds that can vary from a few MB up to 100MB (which git is perfectly fine with), but 900MB is in my experience really rare). Photoshop is just one tool in the arsenal, and not particularly effective for anything involving text (the layout tools aren't great), anything which will be translated to html (just mock up in HTML/CSS after some quick roughs - far less friction), or anything which requires resolution independence (almost every asset nowadays).

Of course this depends on workflow and tastes vary, but for designers who don't use PSD to actually design websites (a purpose for which it is not very well suited), git or other version control tools are incredibly useful. Wasting a bit of extra space storing a few versions of a psd file is no problem - I've worked on 20GB local repositories before with a lot of assets, without issues, and it's easy enough to separate out large files into another repo or leave them out of version control if you have to. If a designer is creating 1GB PSD files with hundreds of assets in, I'd say (as a designer) their workflow is fundamentally broken unless they are producing billboard advertisements which require very high resolution files - you shouldn't have that much of anything glommed together in one file. So git works perfectly fine for lots of designers today, even working with binary files.

It's just a shame that these version control tools are mostly isolated to the workflow of programmers, as people at most workplaces I've come into contact with, from architects through writers or editors, sorely need a tool like git in order to manage collaboration and versions.