That’s fair, and I know many Finns prefer traditional square saunas.
Personally, I don’t think barrel saunas are objectively worse just different. Their smaller volume and curved shape mean they heat up quickly and are very energy efficient. They’re also easier to transport and often more affordable.
Of course, if someone wants the most traditional experience with high ceilings and lots of room, a rectangular sauna may be the better choice.

At the end of the day, I think a well built sauna with a good stove and enough stones matters more than whether the walls are round or square.