The Switch interface beats the Wii U's in one aspect

[sexually_inactive]

Open the Wii U settings and you'll see it's slow. While better looking it takes longer to load and navigate while the Switch/Switch 2's is fast.

 

[Space_Goddess_Samus_Aran]

would say the reason more is not the OS but the hardware

 

[VmprHntrD]

The OS in the WiiU was a disaster, a hot mess. I hate that I had that system when it came out, ever in the end given it was the only system they made I sold off when it was alive because it was that bad. I got mad trying to setup the thing or hit the settings for thing because the first 6-12mo it was around, each menu took 30 SECONDS to get into because it was just a broken code mess. Even 2.5-3 years into it before I sold the pos off, they had only got it down to maybe 5-10sec per screen. Your own firmware should be instant, 1-2sec tops, not be like a PS1 loading screen wait time. That was utterly and completely bad firmware and they were too incompetent to fix it or just didn't care.

The Switch interface may be less pretty, but pretty is subjective because what you need is clean, simple and snappy visuals and menus to get what you need fast and get out. The menus also being nice icons to start are puddle deep, no digging in 3-4+ layers like WiiU did which when you add those 30sec run times were awful.

 

[The Real Jdbye]

You don't even have to open the Wii U settings. All you have to do is turn the console on and see how long it takes to load the Wii U menu.

This is intentional, they wanted to make it load fast so they went the complete opposite direction than the Wii U. Too far, in my opinion. It doesn't have to be as fancy as the Wii U but it doesn't take that much to have a background image and some color, at least. Custom themes with CFW load up quickly enough.

 

[lightwo]

I'd say it's less of an interface and more of a security implementation matter. Copetti's "Wii U Architecture | A Practical Analysis" goes over this:

The experience is not sluggish, but switching between the apps (a necessary common recurrence) takes considerable time. This may be due to the security model in place (recall the bootstrapping process of Espresso and Starbuck binaries) being required to run every single time. Plus, it seems Espresso is not particularly fast for the algorithms implemented [...]

It's true though, this sucks a lot in practice. It even feels like booting takes less time than exiting settings sometimes (at least under Aroma)...

I'm hoping that a modern take on Loadiine will be released in the future, since that used completely decrypted bins/assets to begin with.