With Stack Overflow, its also important to remember the 0th impressions of people finding the site through google.

Finding material that is off topic but preserved for some reason is often cited as a negative experience. The "I searched for XYZ and it was closed as not constructive" (note: not constructive hasn't been a valid close reason for several years).

This brings up the question of "should that material be findable on Stack Overflow if people are having such poor experiences when finding it?" and "are people finding the closed questions of yesteryear a disincentive to participate today?"

The finding things closed as a duplicate sign post isn't working as intended with redirecting them to the proper question - because when there is an answer to the question (that may or may not properly answer it) it prevents the logged out user from getting redirected to the duplicate.