I would love a platform that has collective community moderation through content flagging and voting which does away the need for mods.

This simply isn't possible. If no one has responsibility, the community will inevitably devolve into chaos. Flagging content doesn't accomplish anything if there's no one to actually remove the clearly unacceptable content. If there's no clear rules and no one to contact about moderation decisions, communities just wouldn't be able to function at larger scales.

As for the other part of your comment, first of all it's foolish to use blanket statements and absolutes. However, I wouldn't disagree that some long term mods do seek power. But you also have to consider burnout, as it's a thankless job where you get exposed to the worst of the worst, and if people don't simply quit after a few years, they may become more harsh in their moderation practices as a mechanism to protect themselves.