I understood the point.
Now perhaps the augment is that a certain group of elites, say Toni Atkins and Anthony Rendon can better hold their senators to account than the populace of the state overall. Or perhaps they can at least gum up the federal government better.
But as you said above, the people and the states apparently have different interests. If the state, in your case California, is not made up of its people but by its state assembly, then that's elitism. And in many cases, elitism is fine, but gotta call a duck a duck.
So let's make a thought experiment. California wants, for example, marijuana legalization.
If that is decided on a state-by-state basis rather than a national basis, Californians have more agency as to whether marijuana would be legal IN CALIFORNIA if that power is held in Sacramento rather than Washington DC. If they want something, they have to convince a majority of 40M Californians of their desire, not 330M Americans.
In our current system, if 21M Californians want marijuana to be legal in California, they can't do it because marijuana is illegal at the federal level.
(Admittedly it's a bad example because California *has* "legal" marijuana, but it's not really legal. California just doesn't enforce federal marijuana law and the federal government has chosen not to either.)
That's why I'm saying that state legislatures guarded against ceding power to Washington DC, and why "states" have at times different interests than "people". Because if California has to balance its desires against all the other states, then it has less autonomy to make its own decisions.
It's why there is so much antipathy in rural states--because today they feel like Californians and New Yorkers are telling them what to do. And it's why Californians and New Yorkers are so offended by the "anti-democratic" Senate and electoral college, because rural states are a brake on them getting what they want.
Prior to the 17th Amendment, more power was in state capitals and less in Washington DC, which meant that people in California could have things one way while people in Montana could have them another.
That wasn't always a good thing, i.e. if one state chose to restrict its peoples rights it's wrong.
But by having more power in state capitals, it actually gave the people of those states more control over the policy decisions controlling their lives.