Usefulness of alias/implications decay

I have been wondering for a while the usefulness of the decay of aliases and implications.
For aliases, it makes sense to keep the autocomplete clean, but it still doesn't make sense to decay aliases of the character names in other languages.
As for implications, if an artwork of, say, yousei daisensou, hasn't been uploaded in 2 years, it does not mean that it is not part of touhou anymore. If artworks of an alt of a characters aren't uploaded, it doesn't mean that that alt has nothing to do with that character anymore. Just look at eve (elsword), of the 7 chartags that have been implied to the tag in the past, only 3 remain now.
Likewise, i don't see why old names of artists or names, characters in other languages or utility aliases should decay. It hurts searchability for specific things, and i'm not sure if the benefits are enough.

Bumping

Some changes were made 9 days ago

https://github.com/danbooru/danbooru/commit/a5f589f9e0b574f052fe95c0484b5521d567e99f

Change the rules for automatically retiring aliases and implications:

• Retire aliases to tags that are empty, or that are for a general or

artist tag that hasn't received any new posts in the last two years.

• Retire implications from tags that are empty.
• Don't retire aliases or implications for character, copyright, or

meta tags any more, unless the tags are empty.

This has been deployed. The new rules are:

• Aliases to empty tags are removed.
• Implications to empty tags are removed.
• Now only gentag and artist tag aliases are removed if they haven't had any new uploads in two years. Character, copyright, and meta tag aliases are kept.

Artist aliases are still removed because we have tons of old aliases for old artist names that are no longer relevant.