We've got one-pedal on the Ioniq. I've tried it, meh, I don't see the appeal. It's not horrible, but I'll probably never use it again for many of the same reasons you list.

My dream set up would be the accelerator pedal is, well, an accelerator, and the brake is a decelerator, and if you're not pressing either the car maintains the current velocity.

Sounds like cruise control, which many cars have.