I think you misunderstood my post. I am in no way in disagreement with your reasoning.

Switch is in a really interesting place visually where it's clearly not up to par with PS4/Xbone but on the other hand clearly above PS3/360. It occupies an intriguing middle ground.

The decision to go with a modern chipset for the first time since the Gamecube really paid off for them in terms of allowing them to get games like this, Doom, etc.

physics miles ahead. 

Tbf, world physics in BOTW is above almost everything in ps4/xbox 1 except some cases

I'm still shocked a game like BOTW was able to run at all on a system with as weak a CPU as the Wii U. Yes, it was designed with the Wii U in mind and used twice as much RAM as pretty much every other game on the system, but still. I was under the impression that these massive open world games were harder on the CPU and that was why games like Skyrim couldn't come to the Wii U. Maybe they found a way to shift the burden over to the GPU.

I'm fairly certain Skyrim could've been done on Wii U; Assassin's Creed 3 and 4 got ported over and I'm pretty sure those are harder on the CPU than Skyrim. Same for Watch Dogs and Arkham City actually.

As for BOTW, it's a case of Nintendo knowing their own hardware better than anyone and pushing it to its limits.

Yeah, AC looks better than Skyrim and runs on WiiU. I'd say ACIV (taking art style into account) maybe looks even better than BotW.

Yeah tricky to compare with such wildly different art styles. BOTW does seem to use more demanding effects like volumetric lighting and physics-driven particles.

I was really hoping the other two games would release on the Switch before the third, I don't want to jump in blind...

First Witcher is PC only game (well, Mac is kinda PC also I guess), there was port of sorts in development way back for PS360, but it was never finished. Given that it's very mouse centric game, including combat, there were lot of changes, but deal fell apart in the end. As for TW2, I guess they could've done it, since there is 360 port of it.

But honestly, you don't need to play any of them, there are some references, but overall it's not that important. However, if you do want to play TW2, since TW3 is mostly open world version of it (personally I find TW2 to be a better game), maybe you can play it on PC given it will run on right about anything newer than 2009/10 (and some even older) and it goes for $20 on GOG and Steam.