@cfpct,
I see your point. On the other hand, if you look at the new Bookmarks manager, you can create all of the Stash functions there, at least it seems to me you can . . .
You have Unsorted Bookmarks, and then under My folders, reading list, videos, shopping, travel, and you can easily create your own folders. Why if you want, create a folder in My Folders, and call it "Stash." Put your "Stash" type stuff there. This is separate from the main bookmarks bar. So in a way, they have created something that covers the old Stash functions, but is more organized than Stash. And when you click on the heart to the right of the address bar, when you want to save something, you can easily save it to one of the folders, including, if you create a Stash folder, that one.
Now you say, "Stash was not meant to be neat and tidy." Well, just use "unsorted bookmarks" for that un-untidy aspect that you were using Stash for, or create a "Stash" folder, and put your untidy, Stash-type stuff there. Now if you have items that you want to organize a bit, but don't want to bookmark it, just use the "my folders feature." Put the items there. I like that "read later" folder, because one of the uses I made of Stash was to store in Stash, items I wanted to find time to read, but which weren't worth a bookmark. It looks like what they have done now is quite useful for that.
My initial reaction was negative on the treatment of Stash, but now, I'm starting to see that it may really be okay.