That's the worst misapplication of basic thermo I've seen in a long time.
The key is "like vehicles". Plug-ins and regular gasoline powered cars are not "like vehicles". Electric plug-in vehicles don't get their energy from generators powered by internal combustion engines burning gasoline. For your argument to work, that's what would have to be happening. But that isn't what is happening. Instead, most energy for electric plug-ins comes from generators being powered via turbines. These are much more efficient than internal combustion engines. So until we have cars running coal-fired gas turbines, you can't say "like vehicles".
And even if we restrict the discussion to non-plug-in hybrids, your argument is still weak since non-electric hybrids have a hard time running their internal combustion engines at optimal RPM all the time. In fact, a simple IC engine car must be "detuned" just to provide enough power at low RPM. A hybrid doesn't have that restriction. The IC engine in the hybrid can be optimized for max efficiency since the electric motor will take care of providing power at low speeds.
"That's the worst misapplication of basic thermo I've seen in a long time."
Is it now? Well, just make sure you wear a good pair of walking shoes when you buy that new electric vehicle.
You might bring a thermodynamics book to read along the way, so you can figure out where you went wrong.
Electric cars are only off by an order of magnitude (on the short side) from being actually comparable and viable vehicles - on cost and performance.
If you simply do not want to compare like vehicles, then why not go the rest of the way and just ride a bike everywhere you go?