I'm not so sure about that "hence"Those 2 switches use a double socket size back box, hence 2 gang.
Anyway, thanks for explaining what was meant - and, yes, I agree that the bigger size may be an advantage (although, of course, some people might find that to be aesthetically inferior!).
However, I would hope you would agree that it's confusing and misleading to call it a "2-gang switch" - since that conventionally has a totally different (very well-established) meaning!
Kind Regards, John