Don't they have a .fig format that you can export/import, share? Plus they have the standalone "native" app, so I don't really get you here. Have you tried parsing a PSD file? Have you seen the PSD spec? It's pure nightmare afaik... Are you storing psd resources in git? Probably not. Then perforce? God, have you tried using perforce from the command line? What else do we have for big binary files and versioning? Not svn, not cvs, not mercurial, dunno...

But anyway... we're working with a fairly big (100+ppl) creative agency and they transitioned to figma - it's a joy to work with, I can finally use linux, no need to fool around with windows or a dumb os, the app is fast, exporting is great, collaborative features are cool... I'm pretty sensitive when it comes to apis and data portability, but heck, this tool is a godsend for us.