I really don’t understand how this can be a narrative. We’re not the big, evil companies ourselves, are we? So how do we build something better? The answer is: by simply building it, how else? There’s no difference in the actual doing, no matter whether one hands over the result of the work to an organizational entity which exercises control over who can make use of it under what conditions, or if it’s contributed to a public, open, peer project/organization. Toxicity is hardly an inherent property of the tech or work itself, to the contrary: you have to work extra to add such restrictive and evil measures not natural and in conflict with the tech, so we’re all better off by simply not spending any effort in that regard when it comes to our own tech and activities.
Update: But if, in fact, it turns out that the ambition/goal is to make OGM or parts or branch-offs big tech too, then sure, better avoid the toxicity by remaining with personal knowledge I guess. It’s obviously much smarter anyway 
And then, I too really have to wonder: isn’t the Internet infrastructure by its very architecture decentralized? If you’re refering to the Web protocol/model, which is just one (bad one) among many others, fine, nobody forces the user to trap himself/herself in a vertical integration of storage, UI, remote functionality, name/address, server instance, authentication/access, but that has nothing to do with Internet architecture. Or are you referring to the ownership of the cables in the ground and oceans, or the physical gateways controlled and operated by a company? Are you going to use mesh networks instead? Finally, things like BitTorrent or OpenID or Diaspora aren’t that new, and still, most users prefer the leverage/centralization/“convenience” as artificially enforced by big providers. E-mail works nicely in a decentralized fashion. Homepages, for everyone who wants one.
