The Bag Buddy is close, but not wall mounted... although I guess it could be.
Add liners to make an instant trash can. Sturdy steel frame expands to width of bag used. Collapses easily. Use recommended Clear and Black Liners .
www.uline.com
This one is pretty much what you're looking for. It can be wall mounted or hanging, but doesn't sit proud of the wall. I think that could be pretty easily fixed with some easily fabricated supports made from coat hanger wire or similar.
When I was a kid, I honestly thought trash bags were something like $5 each, from all the bellowing I got from my parents whenever I used one.
Trash management was my chore, but they refused to buy anything but the cheapest, largest bags on the market, and insisted that all trash must be firmly compacted to the density of neutronium so that all the weekly waste from a family of four could fit into one whisper-thin 55 gallon bag in a gigantic, reeking trash can taking up 1/4 of the kitchen.
And then, inevitably, the cheap, overloaded bag ripped open, necessitating the use of at least one more bag, all accompanied by more bellowing and remonstrations for my carelessness and the (also cheap and thin) paper towels used for the cleanup.
Even when I was old enough to do the math and point out that better, smaller bags would end up costing less, we HAD to buy the cheapos and ration them carefully. And no, this was not poverty. Just an unexplained corner of extreme frugality amidst plenty.
When I was on my own, it still took quite some time for me to break the habit so I could buy good bags and change them as needed without cringing. Here in 2024, excellent quality kitchen bags are less than 20 cents each, and I have not jumped up and down in a garbage can for many years.