Linus Torvalds came up with two big inventions—Linux and Git—and of course a variety of smaller but still very useful stuff. But an underrated decision he made was to treat kernel developers working as part of "kernel teams" at random companies as first-class contributors, and not to allow the old OSDL (remember that) to become some kind of gatekeeper organization. So we ended up with the much smaller and more responsive Linux Foundation.
Too bad that didn't happen with open-source web browsers