I'm 100% down with the colaborative > competitive culture. We get into orbit much faster if we build a rocket together than if we spend all our time knocking each others' down. imo Indie creators aught to be setting themselves apart from the cutthrough industry by forming bands that build each other up. Networking for testing, feedback, and promotion of each other's work would mutually benefit everyone involved.
In a way, that's kind of a part of what Itch.io is, in general, but it matters that people can enter into an agreement with likeminded creators, rather than setting up a public system and thinking that is good enough. I suspect there are already such groups out there who are happy with their membership and not making themselves visible to the rest of us. I don't have any work published yet, but when I do eventually get the chance to, participating in such a group would be ideal to me.