It's funny that of all things Apple's watches are square and Android watches are round. It feels like it should be the other way around.
This isn't even new. Casio etc have designed digital square watches for decades because they don't need to be round without clock arms.
A round display suits analogue watch faces but square is better for utility.
E.g. map reading or lots of data fields during exercise. Where you want more display given size of wrist real estate.
Ironically Garmin used to make a square screen Epix but switched to round.
Men’s watches when they are integrated with the bands also tend to be squarish.