What you’re talking about is what I’m talking about, too. In my experience, though, (with two different Windows based handhelds, one of which was a GPD Win, though an earlier model than the one being discussed in this article,) it works sometimes. I’d say it had maybe an 85% success rate, but that other 15%, it wouldn’t resume, or if it did, the game would crash, and a 15% chance of losing my progress is just not something I’m willing to deal with. I’ve had 1 case with the Steam Deck where it did not successfully resume mid-game, total, since getting one just under 2 years ago.
I’ve looked at reviews of a bunch of other similar products but this ended up being a major complaint about all of them. Which one do you have, out of curiosity?