Great idea, except that I don't think it's easy to make sure we don't grant too much power. Basically this idea is the core of representative democracy. Problem is, the people who have been granted a lot of power are very good at finding loopholes to avoid or remove the safeguards we put in place...
There is a trade-off here for sure... I don't agree so much that the goal is to limit power though, but to ensure any power given to leaders is conditional.
I think ideally you want a CEO type leader of a country who has a lot of executive power, but that leader has a board who provides oversight, then ultimately the public are all shareholders who collectively hold the company and it's leaders to account.
I'd argue generally speaking we want to grant more power to our leaders than we do today, but make them much easier to remove and have a well design constitution so certain things are legally impossible in the same way a CEO can't just decide they now have 100% voting rights and no longer need to listen to share holders.
The solution to a bad CEO isn't to have 10 CEOs. The solution is for the shareholders to boot them for a better CEO.