Technically, yes, the offensive does consume like 3x of what is needed for defense the same position, but it works right only if that’s a war of equals. Ukraine was and is underpowered on it’s own, and even with the stuff other countries donated. Them gaining an edge in the warzone in the last years often involved either technological trickery or great insights and tactics using their limited resources.

One other thing that breaks that rule and makes this change in the narrative significant - is that russians could deploy their bombers, fuel, supply centers near the border, thinking they can’t get effecrively hit, that giving them a big boost whatever they do, and if this handicap gets denied, they’d have a harder time supplying another operation from further away.