Shelf mounting adaptor

I made this adapter for mounting lightweight shelves to a wall. In this case, the shelves are a model purchased from Lidl, since the original brackets they come with cannot secure the structure firmly and safely to prevent it from falling.As shown in the photos, the original mounting piece is just a thin metal plate without a hole for screwing it into the wall. Even the slightest accidental bump could detach the shelf from the wall, and these will be used in a children's room.In my version, the screw hole remains visible after installation, but for me it is more important that the shelf is securely and safely fixed to the wall. I test-printed it in black PLA, but of course it can be made from any other suitable material.