I'm pretty sure it has always been the case that a PC emulator could outperform a several years old gaming handheld. At least if enough interest was there for someone to write the emulator.
I'd say that something which is portable is a "portable" even if you can plug it into a TV. It is strongly power constrained. It is just bigger than old portable consoles. (I actually don't know why they were always so small before the Switch. Perhaps large screens were too expensive. Or everyone thought of them as having to fit inside a pocket.)
