Why aren't there any companies using circle pads on their handhelds?

I want to be upfront in saying that I know they aren't the most comfortable form of input. That out of the way, they make for much more pocketable handhelds. For something that only plays up to PS1/Dreamcast/n64/psp I would much prefer this, since it would be easy to slide into my pocket. think something like a trimui Smart pro, but with circle pads. there's a reason why Sony used one on the PSP, and Nintendo used one on the 3DS.

there's just so many handhelds out there that I can't understand why no one has thought to use circle pads on at least one device.

If I've missed something please let me know because I'd be interested in buying it lol