I think the emphasis here should be on "gave everyone equal say". That is still not the case today. Consider that children, foreigners, and some mentally ill cannot vote.
Until a few decades ago it was also customary that women can't vote.
I think it's not a difficult concept to come up with to collect all the people you know in a group and make decisions that way. Lots of societies historically did it that way. I'm pretty sure the germans had their Thing which is just a general assembly for general purposes (including making law). The main difference is that they only included people in the decision-making process who they thought were able to make good, meaningful decisions. Meanwhile today we include everyone in the process.