Kitchen backsplash, which material?

With us, we have wood 40 cm high, the same as with the fronts, someday I might switch to glass, but these 6 meters then cost around 800 euros in ESG with holes for sockets. I don't think it will be worth it for me.

We would definitely choose simple designs like leaves or similar. Yes, glass over these lengths is definitely expensive.

How do we attach a glass cover? Is the glass glued on?

There are special mounts/clips/brackets for that. Nothing is glued.

.. for transparent glass definitely like yours. Opaque glass, because it is colored, can certainly be attached with a few silicone dots.

Has anyone had experience with the self-adhesive films for kitchen backsplashes? Or is glass the only reasonable solution?

You cannot stick the foil directly to the wall. You definitely need another board as an underlay first.

Has anyone had experience with the self-adhesive foils for kitchen backsplashes? Or is glass the only reasonable solution?

No experience, but you certainly cannot stick these self-adhesive foils directly to the wall; it will not hold on the plaster.

Otherwise, there are infinitely many reasonable solutions: painting (with washable paint), tiles, natural stone (granite, marble, but it must be impregnated), glass walls, wall panels made from various materials....