You do realize I hope, that the intention of a red link is a request for someone to write that article. So there is always a chance that that will happen and de page will resurface.
Yet another intention of red link - clear indication “there is no such page created as of now”. If the link is blue - it sends me a message “oh, there is a dedicated page about it”. And clicking it and getting redirect (especially to the very same page I was reading) is useless and not helpful.
Sure if someone one day writes a proper wiki page - it’s great, perfect! But if there is no page - let’s clearly say it
I disagree with this statement. Redirects in a wiki function as keys to a topic, whether that topic has its own dedicated article or just has a short section in an article about a wider topic. I must admit, however that the mention on the Tag:amenity=sanitary_dump_station - OpenStreetMap Wiki article is very, very minimal.
For this, in my opinion, the redirect should not be removed, but the link in the redirect’s target should be removed.
Keeping in mind that deleting the redirect will also break external links that are pointing to it. The chance for that increasing the longer the article/redirect exists. And this redirect exists since 2015.