This is me just speculating and sharing my interpretation of both these frameworks, but I feel like in SwiftUI you get a lot of “try to be nice by default” when you don’t tinker with things. Which sometimes gets annoying, but they are trying to make it more pretty if you configure nothing.
With Compose, it’s always been you get the barebones by default, and if you want something more special, just specify it.
This then applies perfectly in this specific scenario. In my mind, the default of a row should in fact be that items are aligned to the beginning. In the exact same way that if I add a text field and I add some text, it will start painting the text on the top left, and not at the center.
This “nothing special by default” approach is quite nice tbh. And I feel like that’s how this decision for the defaults there was made.