the states should have no say who is on the ballot

I don't think that's really objectively the one way it should work. Why should people that represent millions of people have to be directly voted on by millions of people? Even just in terms of electoralism, that isn't democracy. There is no way you can reach a consensus or most popular choice because millions of people can't agree on something or even communicate. It's hard enough coming to an agreement with input from a group of 30 people.

If anything, you could do the opposite and break down the election of electors into multiple levels of hierarchy, and let each elector vote based on their own political position.

That would ultimately be more like the USSR or China or Cuba, etc.

I think the "flattening" of US "democracy" is more about the fact that it's all a charade so why spend the effort on having tons of elections. Yes it would make sense to just have individuals vote directly for the president, out of simplicity. But that wouldn't make it much more "democratic" other than better reflecting the popular vote that we all think of it as being based on.