When I got my Switch years ago my reaction to the UI was basically "This is it?" It felt like an un-styled working prototype. My thought was "Nintendo rushed this thing out the door to stay in business, surely they'll add some character over time" as they had done with the 3DS (the 3DS started out good but got better).
Nope? I'm still waiting. The only real big change they made was the introduction of their terrible virtual cartridge licensing system.
I genuinely hate the Switch home screen. I would rather be booted into the "More Games" UI instead of this dumb horizontal scroll of a handful of most recent games and then having to scroll over to pick "more games". If you want to be minimal, at least make it easy to pick the game I want. I've got a 65" TV, give me the grid, not 4 titles at a time!
Most of all, BRING BACK THE FUN. Colors, music, silly interactions. Sure, add the option to turn it off, because a vocal minority hate that stuff, but how many of us have the Wii store music burnt into our brains?