There aren't many consoles with libraries as broad as the DS, 3DS and Wii so if you couldn't find something to play on those you probably would find the Switch a let down.
My recollection of the DS and Wii libraries is that they consisted primarily of terrible, gimmicky movie and toy tie-in games like Nerf, Barbie, The Sims, Lego, etc. The more normal games I bought on the DS were disappointing enough that I bought a flash cart, and even playing games for free was disappointing. To be fair to the Wii, it had a lot of those bad games too, but it also had good ones; I never really gave it a chance because I never got used to the motion controls. I still haven't beaten Metroid Prime 3 because of the controls.
But you are right. I'm a picky gamer. I got a Wii U for Smash Bros., which was awesome, and I bought a few more games to justify the purchase and have barely touched most of them (Star Fox, DK Tropical Freeze). Mario 3D World was a fun time waster though; that reminds me I need to finish the last few levels in that game. Hopefully, I'll find something else on the Switch I enjoy.
I just looked at that Metroid Dread game - it looks fantastic. I would love to play it, but dont know about buying console for it.
Maybe PC emulator would be solution...
I just beat it today. It really is fantastic. It's a true successor to Super Metroid and Metroid Fusion. It's neat that people are already figuring out sequence breaks and speedrunning the game in under 2 hours. It took me just over 13 hours.
But yeah, it's probably not worth buying a console for if you're not really into Metroid. The only one I don't own is Metroid Prime pinball, so I guess it's part of the collection for me.
I know I'm 100% picking up an OLED Switch as soon as they are in stock at my local game store. Sure I could order one off Amazon today, but I aint supporting those bastards when I can support my local brick and mortar. I own 15 Switch games and no Switch, so it's starting to get weird not having one.
Switch is a great system, and in my opinion the only console worth owning right now. PC delivers better performance, and basically the same library as Xbox and PS. Nintendo is the only company that offers exclusives not playable elsewhere.
I think your local games store is your best bet. Finding them online is hard unless you want to pay scalper prices. Even Wal-mart's website had a couple for $520 (3rd party seller), which was funny since I couldn't even place a local pickup order for one at the store I bought mine at for MSRP.
I was skeptical about the Switch, but it really is nice being able to play it on a monitor and then switching to handheld mode if I need to take the dog outside or just using the screen separately if I need to use all my monitors. Nintendo is the only system that is compelling since the PC competes with the others.