Great post, @LeoSammallahti! I am a believer in (platform) cooperatives myself. Nice Wikipedia article too.
First, I believe that when talking about root causes, and you go to the actual root of the problems, you end up evaluating the economic systems themselves (modern capitalism, if you will) with their concepts of endless growth and outcompeting your rivals. The focus on shareholders is only a symptom of that.
People often think in extremes of capitalism or socialism, but there are many other economic ideological models that exist and either haven’t been tried, or tried at small scales unbeknownst to most people. Coincidentally yesterday I bumped into Distributism (in the Hacker News discussion 'Capitalism and inequality) which seems very much aligned with the idea of having cooperative organizations.
A cooperative is very interesting, especially if if is funded differently, like by avoiding venture capital. There is a trend to do that. It was discussed on Hacker News of the NYT article Startups are turning away from Venture Capital.
Related to that is the growing realization that striving for Disruption - which is the norm in VC-funded startups - is actually a bad thing, unwanted. There are alternatives that are much more sustainable, like instead of becoming a disruptive Unicorn, become a Zebra (mentioned by @andrewmurraydunn here). Zebra’s have a different mode of operating:
(source: zebrasunite.com)
See also: An epic Twitter thread on venture capital, startups, and zebras (click the date link to read the Twitter thread)