Samus Returns made a certain kind of sense on the 3DS and I think it's fine that that one stayed where it was--it would have lost a lot if they haphazardly bumped it up to the Switch. It's definitely an experience they had built for the 3DS.

Pokemon Ultra Sun / Ultra Moon has looked entirely unsubstantial to me, even in comparison to what Yellow, Emerald etc. have historically added to the original titles. USUM looks and feels like it was supposed to be a quick & dirty Switch port to get it onto a new console generation, but they forgot the most important part of that was to put it on the new console. It has a "Game of the Year Edition" feel to it to me. Sun & Moon were also already very pared down and backing away from 3DS features; they didn't really use dual screen functionality all too substantially and the 3D effects were only used in the Poke Finder minigame. USUM looks like the most underwhelming Pokemon to date --but I'm aware this is entirely subjective and if people are super hyped for USUM then you do you, I'm not trying to take that from you.

Mario Party Top 100 also frustrates me but only because it's a really good idea for a new Mario Party and it feels like it's being wasted by putting it on the 3DS, which is absolutely not where a Mario Party game should be living anyway. I want the experience Mario Party Top 100 is offering, but on a console

I absolutely don't hate the idea of more 3DS games, but the last couple they're coming along with frustrate me only because they feel like they'd be better on the Switch or are otherwise simply half-baked. In the case of games like Samus Returns I'm fine with it because what they were trying to do wouldn't translate 1-to-1 if you ported it up to the Switch at all.