So it's more compact in your pocket, which is where space is most at a premium.

Tallness doesn't make phones uncomfortable to hold (width does), it just makes them poke out of your pockets.

Height does make phones less comfortable to handle with a single hand, which is what I prefer to do most of the time. They are heavier, lean further back so you have to spread your fingers on the back more, and reaching the top to pull the notifs bar, for example, is harder. I'd argue height is worse than width in comfort.