It's not really like that though? Like, the main reason 30FPS was fine back then (and still now, in some cases), is because a lot of those games were made with 30FPS in mind. Hell, if a new game is made with 30FPS in mind, then it's still fine IMO, with 60FPS upgrades being a bonus rather than a necessity.
Like, OOT on N64 doesn't even hit 20 frames most of the time, and modders found that overclocking that game to run at 30 destroys the physics, so the 3D remake was pretty much a big major upgrade for that alone, since it did a 30fps boost properly. I know some who can never ever go back to N64 OOT after playing 3D, while some like me can appreciate both versions for what they are. Likewise, Kingdom Hearts I/II were made with 30FPS in mind, so playing those in 30 is perfectly OK, even though modern versions have 60FPS as the norm and they do feel so much better in that form.
The problem with switch ports and really most bad ports in general, is that they take games meant for 60FPS in mind, and just cut the frames in half for the heck of it. Yeah it works, and sometimes they're optimized super duper well, but othertimes it makes no sense or is done so poorly that it's just unviable to play if you have access to literally any other version. Like, docking this game makes the game mostly 60FPS, so once you play in that way it's pretty hard to play in any other sense. (Though, RIP Switch Lite users in this case) I found the same feeling with FE Warriors and Hyrule Warriors DE (though I was able to adjust to HW in handheld since I feel that was optimized a lot better: probably due to HW running pretty good on New 3DS, though the OG performance was inexcusable there too)
I definitely do focus on gameplay and fun factor most though: for example, Balan Wonderworld on Switch may be a compromised 30FPS port that I'd hate for similar reasons... But having played it in 60FPS on Series X, it didn't change the fact that the core game itself was unfun one bit, so it's not like a switch boost for that game would have made a difference. Or how Tales of Vesperia cuts the framerate in scenarios where you don't really need precise inputs, while keeping 60fps in the instances you do, so it's not like all framerate cuts are bad. They just have to be optimized and not interact with the game's fun factor.