Also, reddit, due to the way it encourages specific niche subreddits to proliferate, inadvertently also showcases, albeit from the tag side instead of the tagged-content side, one use-case where community tagging is both necessary and canonical tags are inconsistent or nonexistent, which is the vast arena of porn, which involves attempts to categorize massive amounts of content that are frequently lacking in tags or tagged minimalistically or even erroneously by studios, and also, can involve specific preferences that aren't necessarily even considered as something that needs to be tagged until someone starts a subreddit on some really obscure aspect of a clip and then, suddenly it turns out there's a community and demand for such a tag.

Some automated tagging solutions do work on some aspects of the tag deficiencies - performers using different stage names, for example. However, just as obscenity is defined on a "I'll know it when I see it" basis, individual and perhaps previously unnamed categorizations pop up frequently enough that there's no realistic way to anticipate every future community tag that may come about. There's also inconsistencies as to how currently-used tags are defined, and even in the generally more centralized and almost over-specific niches of the industry in Japan, with consistent and unique product codes for reference, you still don't get a single consistent studio tag system, even for their domestic mainstream market. And language certainly factors into all this, as well as culture. It's already evident that some tags translate and some simply don't, either because there is no word for it in the other language, or the categorization loses some aspect of cultural significance in the translation process that makes it end result valid but also nonsensical. Some degree of community curation to augment even a relatively consistent, centralized, and comprehensive canonical source.

There are a few projects on Github that are hashing out compatible systems for at least the English language (and it appears that projects in Korean and Chinese exist too, also on Github). This is definitely an arena that is organic, disorganized, and even if in the future can mostly be automated, will always have room for community curation, and is actually actively being worked out and evolving in real time. Tags, or community curation at large, will likely persist as content, the market, culture, CV/classification tech, and mores change as time goes on. Definitely not dying.