Being able to build such large scale cool things just out of desire was and still is the privilege of those who come from the right socioeconomic, privileged background. People who don't have any fear of feeding their families, making a living into the next decade. People who can easily get a well paid job at any moment. People who have connections to be able to get donations and raise money. Same with Wikipedia. It was not started by some random dev who came from a poor working family.

Building such large scale things was never the domain of 'common' people. They were able to act as contributors to such projects and they were able to create and run smaller scale projects like Open Source Software, but big things were always dominated by those from the privileged background.

DAOs change that. They bring the means to engage in large scale economic organization into the hands of the common people. That's why they are important.