https://en.wikipedia.org/wiki/The_Logic_of_Collective_Action
Or look at the case of Mozilla which seems to be at least treading water when it comes to browser engineering but in terms of marketing and legitimacy they seem to be doing as little as possible to threaten Chrome but keep plugging along because if Firefox went down then Google might get pulled into antitrust court. (Think how Microsoft funded Apple during the dark years of the 1990s to keep competition alive or how the existence of Android must have a huge value to Apple today in that Apple can claim it has competition -- competition like the heel in pro wrestling)