But… google’s normal results aren’t sorted chronologically descending either. There’s, like, 20 layers of mystery algorithm in the ordering. What does “oldest website” mean anyway? Least updated? Oldest registered domain? Time stamp on index file?
Reversing the list would just show the “least relevant” first. Heavy scare quotes on that because what Google considers “relevant” these days is a lot more to do with who pays for more ads for them than anything to do with information quality, sadly.