And what if the page is one of perhaps 80+ very similar pages that each carries a different weather-satellite image but has no uniquely searchable page text?
Well, maybe a manual tag system.
while i do think tags are a nice addition and can simplify bookmarks for those people that have lesser needs for their browser they have one big issue for bookmarks that you dont use very often: having to actively remember stuff. In the case of seldom used sites (which you might have a few dozens of) that you only need to access every few weeks or even months you would have to actively recall what tags you might have used to categorize these pages. having a multiple layered folder structure allows you to see what you actually bookmarked, then access the folder you wish.
Tags might be able to replace bookmarks for some users and if that's the case for you you can simply not bother with the bookmark structure at all and solely rely on the tags you enter when bookmarking a page. But the majority only use them as an enhancement, for quite a big number of people (including me) they can't replace structured bookmarks alltogether.
What some people don't seem to realize is that their use-case is not everyone elses use-case and other people might have a different workflow. Just because a change in a feature doesn't affect you doesn't mean it's not a bad change. Just because i never used mouse gestures - and still don't - doesn't mean i can simply deny the fact that removing mouse gestures (are they back?) was a bad choice and should be reverted immediatly. A few of the "defenders" (sorry for the bad wording here, i could not think of a less extreme description) appear to do this with a certain degree of fanboyism (again, as a person whos first language isn't english i can't seem to find a more appropriate term here) denying them the cappability to see when their application/product of choice (in this case a brwoser) takes steps into the wrong direction.