Raised bed made of concrete blocks - to glue or not and use of foil?

I understand that. But the question of stability depends quite significantly on the size. Larger stones simply forgive more mistakes in construction. Basically, it also works with smaller stones. See, for example, the video Hochbeet mit Klinkersteinen from Florians Gartenwelt on Youtube. I find it a bit daring for laypeople.

Well, he can also try with the raised bed. If it doesn't work out, worst case he has just burned a few calories for nothing.

So it should not fail because of the masonry, especially since it is a thin-bed adhesive method. And that was already quite easy to do during the house construction.

The stones measure 40x21x14 cm.

So it shouldn't fail because of the walls, especially since it is a thin-bed adhesive method. And that was already quite easy to do when building the house.

The stones measure 40x21x14 cm.

If you know that... then why the question?