Using the example of organic Birchermüesli:
39g sugar = 43% of the reference amount for an average adult (8400 kJ / 2000 kcal), if 90g (!) sugar is taken as the daily reference value!

These are the guideline values adopted by the industry: https://de.wikipedia.org/wiki/FoodDrinkEurope

WHO and SGE suggest 50g per day, whereby the following can also be read from the WHO:
https://www.welt.de/wissenschaft/article138077917/WHO-empfiehlt-6-Teeloeffel-Zucker-pro-Tag.html

This means that a single cup of organic Birchermüesli contains 78% of the sugar at 50g/day and as much as 156% of the recommended maximum amount at 25g/day.

Migros has never been interested in reducing the sugar content in its products, even though we keep reading about it, as with yogurts.