Vertical arcade games are one of the reasons I like the Powkiddy RGB30 so much. It makes good use of the extra screen height. It’s also better for Gameboy, Gameboy Color, and Pico8 than anything.
I have never used a handheld that worked well for me sideways for vertical games. There usually isn’t any comfortable way to hold it. The extra height of the RGB30 makes it more comfortable in general even though it’s just a flat slab of plastic. If someone made a more ergonomic version of that layout in the same pricerange, I’d probably buy it.