There is actually a difference, the Switch allows you to lie down on bed and play the game like using the iPad instead of just sitting down on a coach and chair to play on it.
I remember how tickled pink I was by Super Mario Bros 1 coming to the GBC or Mario World on GBA back in the day. Now I can play Witcher 3 & Skyrim in the backseat of a car. Even with online-only games like Overwatch, there's always going to places with free wifi like Starbucks or McD.
Mostly it's that it's now portable. I already played plenty of dark souls and spyro, but being able to take it with me is kinda a big fun deal, so those remasters look real nice still.
As far as old game on portable console I had my fun with PSP. I could play any psone game (unless it really needs L2/R2) and also emulate Super Nintendo/famicon games, Mega drive/genesis, game boy, a bunch of old arcades...
It does seem a bit silly on the surface, but I suppose one useful aspect would be that the game works (assuming games ported to the Switch work reliably). When I get an older game through Steam, I am genuinely surprised if it runs the first time without having to google some technical issue.
The Switch allows to (a) interrupt gameplay without loss of progress at any time, (b) play whereever I want. By contrast, on PC I am bound to sit in a chair even more, and if I pause by Alt-Tab I'll have to deal with a noisy fan. Recently I prefer even mobile games over PC games, except for Warband.
So for me the Switch makes the difference on whether I even WANT to play the game.
... Even the though I didn't have nearly enough time recently for games, and sent back the one I ordered, since it was delayed by more than a week and meanwhile the revision had been announced...
Correction. They're old games that are getting a release to a portable system.
You're seriously not excited for the Jedi Outcast games? Oh, I forgot, if it's not some lame as shit mmo, you don't care.
Yeah, I mean it's so obvious and people are still dumb enough to fall for it. Not me though. Now excuse me while I go play FF8 Remastered on the Switch.