Just an arXiv with peer-review is not enough. There is a lot of room for innovation and improvement. There was quite an interesting discussion[1] about creating something in between Overleaf[2], ArXiv[3], Git, and Wikipedia, moreover with the ability to do a peer-to-peer review, discussion, and social networking. Check out the last[4] article in that series. There are a few implementations, albeit not covering all features, like Authorea[5] and MIT's PubPub[6] (it is the open source[7]). See also GitXiv[8]. See also the Publishing Reform[9] project. Moreover, there is quite an interesting initiative from DARPA, to create the scientific social network of a kind - Polyplexus[10].
[1] http://blog.jessriedel.com/2015/04/16/beyond-papers-gitwikxi...
[2] https://www.overleaf.com/
[3] https://arxiv.org/
[4] http://blog.jessriedel.com/2015/05/20/gitwikxiv-follow-up-a-...
[5] https://authorea.com/
[6] https://www.pubpub.org/
[7] https://github.com/pubpub
[8] https://medium.com/@samim/gitxiv-collaborative-open-computer...
[9] https://gitlab.com/publishing-reform/discussion
[10] https://polyplexus.com/