Those states would never have signed onto the constitution without the senate. It’s not ‘artificial’. It’s a core part of why the USA came to be.

Articles of confederation. This is also why the southern states were called the confederacy.

Why do you seem to believe anything I'm talking about involves the Senate mattering?

I've discussed how the House had its membership artificially capped roughly 150 years into this country's history

Because the senate does matter.

The system is setup to balance out two competing interests - the large cities (with large, concentrated populations) and the states (most of which are not so heavily populated, but have most of the land and resources).

It’s a compromise. And necessary for the Union to be balanced - unless Montana, Wyoming, South Dakota, Utah, etc. should now just become (defacto) vassals to Los Angeles. Which they definitely didn’t sign up for.

Again: why do you seem to think I don't understand how the senate works.

The senate works the way it does. The house is intended to be the chamber of the populace. Roughly 100 years ago we artificially limited the house of the commons. The senate never changed.

So why do you keep bringing up the senate?

I said why. Because if the house hadn’t of been capped, it would have thrown the entire system out of balance, and all but a handful of mega cities would control everything else.

That was never the deal. In fact, that was clearly not the deal.

And since those cities depend on the resources of those surrounding areas too, it can either be a symbiosis or a war.

The states had governed themselves for 150 years before the revolution (same age as USA in 1930s), they weren't going to give that up. Also overlooked is that the states had different religions and spoke different languages. We assume they were destined to unite only in retrospect and forget how improbable it actually was.