The exact same trick works with custom search engines in Chrome as well.
They're equally powerful. Automatically adding search engines means users don't have to do so by hand, but you can still manually create a "search engine" too (e.g. "https://xkcd.com/%s/" with the keyword "xkcd").
In Firefox I keep a folder with bookmarks that have keywords, but I would prefer the UI in Firefox's search engine settings (the bookmark manager doesn't have a keywords column).
The problem is few will discover Firefox's bookmark keywords unless they're told about the feature, and manually create such bookmarks, while Chrome automatically creates keywords for search engines and prompts users to try them out.
I completely agree that it's a pity such nice feature isn't known better among wide audience and yes, Firefox bookmarks management ("Library") UI leaves much to be desired. [2]
Just one reminder: in Firefox there is "Add a Keyword for this search..." command on any (form) input field that triggers keyword bookmark creation wizard [1], so what Chrome does automagically by visiting page with form (or using the form once?) you can do quite easily in Firefox as well, but you must find the input field, shift+f10 or click few times and pick keyword.
Also, using same keyword for different URL will (at this moment) silently "transfer" the keyword to new URL, with no warning about
[1] yet again, this wizard obscures resulting bookmarked URL with relevant `%s` part, so regular user cannot find out how this thing works. (I'm sad how hard recent browsers tend to hide whole concept of URL from users, in general. I understand it, but it's sad.)
[2] I had to `select moz_keywords.keyword, moz_places.url, moz_places.title from moz_keywords inner join moz_places on moz_places.id == moz_keywords.place_id order by keyword;` last time I wanted to see all my keywords. (And I'm trying to keep them in a single folder as well.)
> I completely agree that it's a pity such nice feature isn't known better among wide audience and yes, Firefox bookmarks management ("Library") UI leaves much to be desired. [2]
My main worry is that I mainly use tags to sort my bookmarks before using folders, and even after many years they (tags) aren't showing up on mobile. I'm afraid they'll eventually pull tags support out and become way less useful.
Tags are IMO a better sorting system than folders.
I've ended up using neither tags nor "topic" folders (besides few folders in toolbar): for retrieval I rely on titles (names) and URLs alone. Every time I bookmark something I evaluate its title and URL, look for missing terms my future self could use, and then either reword the title or add raw "tags" in the end. Extraordinary bookmarks I supply with several * proportionally its extraordinarity (and make sure names contains no such sequence).
It serves me well: using native bookmarks search accelerator [1] in url bar * , keywords and 'rating system' allows me to for example quickly pull "best personal blogs of people writing about javascript":
* *** javascript guru
I understand your worries, IIRC there used to be bookmark "description" field that was just recently removed (I've used it maybe twice) and if tags are globally used like this description was, your concern could be quite relevant. If need arises, perhaps some sqlite-fu could transfer tags to titles, at least.
