Google is just trying to help users realize that the web is a bad source for organized information. Google sells expensive clicks to personal injury lawyers off of titanic spam plantations of SEO content —- their mission is orthogonal to the organization of information.
Adding tags has a chance of causing user confusion, UI congestion and impact on existing tools (in the case of Google Drive) so it's not a free thing to do.
Based on the snippet linked, not exactly thst.
For example one of the thing the book says is users of earlier Windows versions used hierarchical structures.
To which I point out: the only alternative wasn't tags but a flat non-hierarchical lack of structure.
Another thing: The Gmail team got it kind of right, they introduced hierarchical tags.
Sometimes one solution is obviously better and you just need to get the knowlegde out.
Other times there are good reasons to keep both: I personally very much want to have both folders and tags.
At no point should one however take the modern ux trick: hide the power tool, use the fact that no one use it anymore as proof that no one wants it and then remove it.
Not giving features for self-organization is a choice.