Just leave the trash in the supermarket
It's best to leave superfluous packaging in supermarkets right there. Supermarkets are obliged to dispose of packaging.
The more you leave in the supermarket, the more you have to dispose of. Sooner or later the market will tell the manufacturers that they don't want to dispose of so much packaging anymore.
You also have the possibility to report packaging via app here in Germany. At Replace Plastic you can report packaging, scan and submit. The organisation sends the requests to the companies by e-mail. A few companies have already made positive changes. And in the app you can follow what has been reported the most. This way you will quickly realize who the global players with insane packaging are.