Accessing Upper Shelves of 8 feet high pantry
I mean what you are talking about is a sliding ladder - picture below.
I worked in a french bistro in the 90s that had one for storage.   This is basically the only thing that will get that high and deep along a long width.   If done right it would be &quot;cool as sh!t&quot;.   If done wrong it would be an eye sore and in the way.   Another part of this is how big your kitchen is.   A humungous kitchen could support this.   A large kitchen that had just one wall that needed it could do it especially if there was a nook to fold it away.