Rather than abolish the Electoral College and merge the House and Senate, I would suggest massively increasing the size of the House. This would increase the size of the Electoral College too, reducing the distortion of the population while still protecting less populous states. This also has the advantage of being something that can be done through ordinary laws instead of Constitutional amendments.
People in flyover states do have legitimate concerns that are not priorities in California, Texas, and New York. Massively increasing the size of the House solves the problem with the tiny states where there are fewer people per representative in the small states, while preserving some power for them in the Senate.
If you only did representative by population, Wyoming and Vermont would essentially be cut out of the national political process entirely. The tyranny of the majority can be a dangerous thing.
That's because you have a limited view of the world based on your circumstances. You, like most of us, don't understand other people's needs aren't the same as yours.
Therefore, we should make sure that everyone has a voice when decisions are being made. The tyranny of the majority is a dangerous thing. Unfiltered mob rule is no way to construct a society.
Certain firearm restrictions are an example. Nobody living in downtown Chicago needs a high-powered rifle in their home. So according to many people owning them should be outlawed.
But someone living in rural areas may legitimately need firearms for hunting, dealing with predators or hogs, or self-defense because the nearest law enforcement is 30 miles away.
Most people just want common sense regulation on guns, not an outright ban, and it can be more specific to cater more strict regulation potentially depending on density.
So what you're saying is that a one-size-fits-all solution isn't realistic, but we should have a national government that's not designed to give voice to those who live in less-populous areas and therefore have different needs than those in High-population areas?