Let's face it, no one uses the 'posers & puzzles' forum.

Options for replacements:

*Green ink letters - a forum for lunatics to rant about conspiracies, guns, religion, wastes of taxpayers' money, etc etc.
*Pornography
*Help 2 - A supplementary help forum, for non-chess related help (e.g. 'my wife is having an affair...'😉
*re:cycle! - a forum about bicycles
*LGB forum - A forum to explore lesbian, gay and bi issues.
*Sweets I remember - A nostalgia forum, slanted towards sweets, chocolate bars, and other treats.

I'm sure there are others.

That does indeed Pose a Puzzle.

With what do we replace the Posers and Puzzles Forum with?

I'm for keeping it. All the other subjects you mentioned can easily,
and often do, get an airing in the General forum.