It’s a Japanese artform, they can present it however they fucking please. They have been writing their language from right to left for thousands of years. Seems like a pretty functional system to me. But I’m sure you know better.

But think, for a second, what it would take to reverse the order. You would have to move the bubbles completely and make them a different shape (horizontal rather than vertical). That would be a nightmare to “translate” (using quotes because it would be far more than just translation). You would need to redraw nearly everything. You can’t just flip everything horizontally, because the bubbles are still the wrong shape and any writing in the background will be visibly reversed.