michael adams wrote
Rod Speed wrote

Like hell it does. Nothing like as easy to make completely
rigid vertical frames that support the shelves,

Unless you want the thing toppling over, you need to screw it to
the wall at the top, whatever its made of. Steel, wood, whatever.

I said that in the bit you carefully deleted from the quoting.

Once its screwed to the wall at the top, in two or more places its rigid.

Pigs arse it is if the frame isnt made properly.

Much easier to do that with welded Speedframe.