Because for official numbers they use shipment and precise data because of regulations, for marketing PR they use their sold through estimative that can be a little imprecise.

And people please stop confusing being on shortage/sold out as 100% sell through... yes everything shipped is sold whenever available on the store (which also makes the staggered release irrelevant since if they had released in all markets at once they would have less inventory in each because it would be spread out. Also explain why Sony had smaller shipment in some periods, because it was saving some inventory to send to a release in a new market), but still it takes some time between shipping (going out of the manufacturing plant) and arriving to the store to be sold, actually several weeks (reason why VGC considers reasonable at least 1 month of weeklys sales as difference between shipped and sold, and if you go and check official numbers from Sony on the quarterly reviews and VGC sales on the same date you`ll see something like 500-800k difference for PS5). So yes if Wii was at 10M shipped and PS5 at 10M sold through at the same number of days it means PS5 had achieved 10M sold to customers about 15-30 days earlier than Wii because there would need some time for the shipped units to arrive and be sold even if sold 1s after delivery it would have took 2 weeks on the ship. It is not that hard. As everyone said don`t need so defensive, soon enough the Wii curve will be in a position PS5 won`t touch, until well it pass through on the year 5 or so.

The recent Sony financial report for the quarter has revealed a 70% digital split for software sales. And this is with the majority of PS5 consoles being disc based! The digital transition will be a major reason why Sony will break industry records year after year.

But not to forget that even though some moved 100% to digital and others even buy most there they still prefer the disc one for options.

Also, no innovation.