I'm actually a bit surprised that Switch has its best week 7 and 8 after this mediocre holiday season.
On the contrary, a mediocre holiday season can translate well to a strong week 7/ 8.
The reason of course being stock. Some sales might have been shifted to now from the holiday season due to stock issues. But of course Pokemon Arceus is helping a lot too for this boost.
As for PS5, it is interesting that Sony decided to provide good stock for Horizon, but they seem unable to hold stock for other releases.