It's thinner, but at 165 grams it's not appreciably lighter than a regular-sized iPhone (the 16e in particular at 167 grams). People generally want a more lightweight phone more than they want a thinner phone. So it's only for people who also want a larger-than-regular iPhone screen.
Of course, but if your main concern is weight and you don't necessarily want a larger display (or would even prefer to go smaller than 6.1"), then it fails to be an improvement.
