It will take some time for enough users to be blown away by how useful this is.
I wrote a simple user script one time that subscribes me to all discoverable rss feeds I run into while browsing. It seemed rather random but I was blown away by how interesting the websites I visit are to me. You can imagine it, now multiply that by 10 000 and you have a good estimate.
Google has to index 130 billion pages and is barely able to deliver half interesting results. If you query it with something like "Firefox" or "Google" it will find zero interesting pages. Stuff so boring you won't even bother.
In your history there might be hundreds of interesting articles, discussions, lectures, publications etc interesting to you specifically!
That obscure website you once visited, that one without any traffic, visited by Googlebot one time per week which then bothers to index 5% of it and puts the results on page 20 of the search results. Why it even bothers to index it no one knows.
Now say you want to read it again or you are searching for that obscure thing again 5 years later it is there in your history.
Mozaïk had full text history search in 1994 when hard drives were 5 mb and the www had 10 000 pages. The www now has a hundred thousand times as many pages but drives are a million times larger. Unlike 1994 you won't be able to visit a single digit percentage of it.
I’ve built something similar myself. It’s quite annoying that the browser only saves like 3 months of history.
I can understand the default not keeping forever, for privacy, storage, and performance reasons.
Writing comments takes only slightly less effort than writing a draft for a book. The Twitter or facebook history, even our comments here quickly lose value. It all vanishes into the hole.
In contrast, i once ran into a geocities page created by a very elderly couple in the US about their vacations. They were old enough to tell the story about how the world changed over time from an appropriately mundane perspective. They probably died before I found the homepage. It was an oddly interesting read. In 100 years it would be truly marvelous.
If the software is there we could probably wrap the proverbial Richard Stallman's browser history into a product worth buying. It would be every bit as funny as it sounds.
Firefox is, what, 3% of the browser market today? It isn’t because it’s a bad browser. It’s because people are using OSes with tightly integrated browsers they never think to change. Making Firefox faster or adding vertical tabs or whatever the demand of the day is won’t change that.