Don't care still counts

That's no excuse, if you plagiarise bad stuff I will come after you for it because karma

Are you in the US?

They all gave their own heating elements to adjust the water temp, but they take time to heat up those couple of gallons and the elements design isn't as efficient as a home water heater, so the cycle length is shorter if using hot water and the energy is more efficient than begining each cycle with cold.

Than they are installed incorrectly. They get installed on the hot line.

They have a heater since the hot water isn’t hot enough, but you can give it hotter water to be more efficient.

Yes, it’s more efficient for you to heat the water instead of it doing all the work.

Most ones are or should be. It's more energy efficient on electricity than the dishwasher heating element to heat the water, and many newer (like last 20 years) dishwashers are designed to be plumbed to the hot water and their built in heating elements are smaller and do more for just maintaining or slightly heating the water instead of heating completely cold water to hot.

I said just the top rack alone. I didn't list anything on the bottom row.

Top of the line vs medium of the line. My old dishwasher I could load however I wanted and it would get clean, can’t double stack with this one.

I think it’s how the spray arms are designed, my current one has 6 holes per arm, where I think my old one had 18 or so.

They come with the place you are in

I'm assuming you either pre-wash your dishes, only use them for things that will come off with a light soak, or have a lower standard for clean.

Because based on my personal experience, packing this close guarantees dishes are going to come out with oily residue or crusty bits towards the top where the water jets can't reach.