Oh yeah, most definitely true! When I used Parsec in the past, it was when I was playing around with game streaming and that's often more latency-sensitive than something like using my video editor, though I'll also need to see how it is for frame-perfect transitions/effects that I want to align to audio.
But for me, the use case isn't to reuse underpowered machines to backhaul to another machine - my M2 Max is powerful enough for anything I want to do (though I'm likely to buy an M5 something after they're released since my warranty on the M2 will probably be up around then) and I can just pick it up and carry it with me. For me, it's more about putting the editor on something with fast access to the underlying storage. Even though wifi has come a long way, it still sucks, in my experience, for editing high-bitrate footage from a nas (proxies would help, I'm sure).
I'd be likely to still do color (and maybe fine tune audio/video sync edits) with the laptop on a wired connection through the dock, but as a silly example, I did a 48 hour film project a few weeks ago and at some point, one of the people is hallucinating some burnt toast talking to him. We ripped a little mouth in the bread. For the 48, I just warped the image for the hallucination, but now that I'm working on the extended cut, I'm animating the little mouth to move with the words. I suck at vfx since I barely ever do them and don't like them much so it took me a bit over an hour to get the first 3-4 words done. The next clip has about 10-12 words. They should go a bit faster now that I figured out what I'm doing, but... still probably a couple more hours. I'd rather do that lounging on the couch while watching a movie at night vs hunched over my desk. Maybe Parsec is my shortcut for that. That and there's another part with a transition that I can't nail down to where I like it, would rather play with that while comfy on the couch too.