[Jnr]

Someone linked the "parallel to the wall" hanger here https://www.amazon.ca/Retractable-Adjustable-Wardrobe-Clothi... and it costs a lot. If you want to put multiple ones next to each other, it becomes quite expensive.

Also access to items behind other items becomes harder and slower. And it requires a shelf above to secure to.

Horizontal pole and foldable hanger design still seems like a simpler and better approach. The design seems so good that I bet you will be able to order these from China in a couple of years for less than a dollar.

[wodenokoto]

Ikea has them for pretty cheap, though they are made to fit inside their closets.