Solarpunk

In an ideal picture, ground isn't where energy gets dissipated

there's no such thing as "dumping energy to ground" (or if you prefer, everything is "dumping energy to ground").

If ground dissipates significant energy, this has all sorts of Very Bad implications. For starters, the ground can no longer be at uniform potential if it dissipates

so now we have a ground that isn't actually at ground! (This just follows from Ohm's law.)

Another way of stating this is to imagine what sort of circuit you need to "dump energy to ground." This is probably just a wire connecting hot to ground

but what happens if you do this in your home, i.e., plug a wire from hot to ground (please do not do this!)? It gets really, really hot, and will probably either throw the breaker, melt, or start a fire. The reason it gets hot is because it's the wire that dissipated the energy.

Ok. So the reason the wire gets hot is because it has finite resistance. So what if we choose an imaginary superconductor instead? Well, now we're trying to draw infinite power, which is bad! In practice of course it won't be infinite, and will be determined by the resistance of the power lines feeding it. But remember that wire that got really hot? Now we're treating the power lines that way. So this is really not good, and besides, we wanted to use a controlled amount of power, which this clearly isn't.

So, we can be smarter here and add some resistance to our load

instead of a wire from hot to ground, we now have maybe a coil of low-but-finite resistance wire. This works great, and it's just a resistive heater.

The problem isn't dumping energy at a human scale (e.g., an individual space heater)

the problem is when you have excess power on an industrial scale.