That's very strange definition of failure: many non-homogenous systems have Pareto distributions. That in itself is not indicative of failure.
30 years ago, AOL may have been most popular email provider, it was displaced by Hotmail, then Yahoo, now GMail. Having different leaders over time is evidence of the resounding success of email federation, those domains still exist and can still send/receive emails universally. If email had hypothetically been non-federated and proprietary to AOL, it would be dead today (or as close to it as gopher)
30 years ago, AOL may have been most popular email provider, it was displaced by Hotmail, then Yahoo, now GMail. Having different leaders over time is evidence of the resounding success of email federation, those domains still exist and can still send/receive emails universally. If email had hypothetically been non-federated and proprietary to AOL, it would be dead today (or as close to it as gopher)