The bigger story here is that you expected different, given the variables at play.

This has been covered in exhaustive detail.  PS5 software is heavily skewed toward digital sales.  And logically it should.  If Nintendos next console offers meaningful storage space, expect physical sales to drop in kind. Let us pray.

To be frank I am a fan of physical options but in the age of required downloads where sometimes disc's are nothing nore than download keys...

Of the PS5 games I own, I only bought one disc (the new Tals of... which Amazon had on sale for half price.)

Hm, Ys memories: The Oath in felghana opened at nr 7 with about 6k in sales. Is this good or a flop?

It's a remaster of a 2005 game that is a remake of a 1989 game and Ys isn't very big in Japan. I think it's decent.

Just saw that PS5 is actually doing better than PS4 in Japan.

I wouldn't think so. Compared to PS4 it still doesn't have any big exclusive in Japan. Ratchet is currently the biggest exclusive on PS5 but Ratchet isn't popular in Japan 

You don't have to think when we have objective sales data lol

Hogwarts Legacy has essentially acted as the biggest PS5 exclusive since it was exclusive to the platform for 3months,but even titles with cross gen from day one (GT7/Elden Ring) have acted as system sellers.

Physical software sales are significantly worse on the PS5 than they were on the PS4 launch aligned. Hardware sales are what is better.

What I don't understand is why there is no data about digital sales

Oricon has been tracking digital sales and streaming numbers for music, books, comics and home media for ages now

I assume that's a given considering the digital rate for Sony is much higher in 2023 than it was in 2016.