Ok. Ill admit that at one point in time I was assiduous about filing my bookmarks.
As all 'filers' do, I quickly ran into problems, though. In an ideal world, with a highly 'curated' filing system, each folder would *ideally* become like a keyword for 'finding' the bookmarked resources again. Except that firefox does not search the directory names when searching thru your bookmarks. Seriously?!? Big flaw, but true.

And in the end, shallow folder structures (1000 sub-folders in one root folder) are not much different than flat folder structures (1000 files in one root folder) in terms of search-for-rediscovery. So, of course, you use the nesting or hierarchical 'feature' of folders to make folders-within-folders. Great hunh? Except when you nesting becomes so deep that you have to click 6 times or more just to drill down thru the folder structure to get to a damn bookmark.
Then you have to sift through all the bookmark your target folder contains. And if its not the 'right' folder? Start all over again!
This problem is compounded at points where I would ideally want 1 resource in multiple folders. Really, what this means is that I could think of more than one reasonable path for rediscovering that resource; or more than one reasonable classification, attribute, or feature that stood out to me about the resource.
For a while I experimented with double/multilple-bookmarking, but honestly that sucked. It made me hate to *think* of 'where else' a resource might 'belong', because in order to file the resource you need to drill through a directory structure, t,,. As many times as 'keywords' you would like to associate with the resource. And in a large (deep) folder structure, it is soooo easy to get lost! And, honestly... lose interest.
So filing bookmarks became an annual thing. Anyhow, over time you fall out of touch with where you put stuff last time, and slowly start creating new, *equally 'sensible'* places to keep things.
I found that over time I eventually recreated parts of my folder structure multiple times, which would mean that some folders had multiple twins throughout the directory structure *that did not contain* the same resources, *but should have*! With identical fragments of directory structures appearing throughout the whole, synching the contents of bookmark folders became a big unmet need. Still havent found anything that will do that for me.
I soon decided that duplicate bookmarks were structurally a waste of 'classification' space, and wanted to get rid of them. I also eventually decided I wanted to prune dead links from my collection. Luckily I found tools for both of these tasks.
Ultimately, what I wanted to do was use folders to attach keywords to all the resources I bookmark, and then search by either the 'official name' and description of the resource or by my own description of it. Ideally, if you put a resource in a folder at the bottom of a deep folder structure; it ought to 'inherit' all of the keywords (i.e. folder names) of all its parent folders. Wicked ideal would be to apply a hierarchy or group of keywords 1) without drilling down thru folders and 2) with the specified relationships between keywords intact.
As I have alluded, I have put massive effort into 'filing' bookmarks in folders that have names (and releations!) that I basically wanted to act as tags; but could not because of limits in the technology.
Now the technology has changed, and it is now possible to TAG bookmarked resources. So what I really need is to be able to convert my previous classification efforts easily. Ideally I need an app that converts each element in the bookmarked resources 'path' (the folder names for the entire directory structure i previously dreamt up and dropped each bookmark into) into a searchable TAGs.
IN the new Bookmark tagging system, the location of the bookmark is *nearly* inconsequential. What is really important is the tag attached to it.
But maybe we shouldn't be so quick to ditch folders. One of the nice side-effects of using folders to store things, is that (if folders hierarchy & names are carried over as nested or related Tags) everything in a given folder necessarily has the SAME TAG/Folder name. Thus, so long as you control for folder duplicity, filing using folders is good for Tag consistency.
So using a Firefox extension, I have been able to do just this. I have converted the names of all folders in the Bookmark directory structure into tags that apply to the documents contained by each folder. Thus, I can call up child tags by recalling any element of the previous folder structure. And where fragments of the directory structure previously meant that you might have to search multiple paths to find all relevant resources, now they are all 'virtually' in the same folder/tag group. Wicked.
Now i just have to deal with the issue of changing folder structures creating orphaned (and useless) tags.