> The tendency of Wikipedia editors is that, when an article is many years old, they would rather flag it for improvement rather than simply throw away years of fellow editors' work.

That's not been my experience, tbh - in my view the deletionist fraction of the editors has essentially "won", if one can put it in those terms. I _think_ there is a (maybe small) group that have decided it is their mission to guard Wikipedia against what they view as cruft or non-notable, regardless of how many years of work these articles may have accumulated. They do not need to be paid for this - they enjoy it. Destroying is always easier than creation.

I seem to recall some study showing that the vast vast majority of edits/deletes on Wikipedia are the work of just a few hundred long-standing editors (citation needed) - which to me confirmed my gut feeling that most new editors bounce off and give up on contribution in short order.

I contributed for a few years, but gave up eventually - it was exhausting to spend time collating sources, collecting information, editing, rewriting, and then having someone come along and propose discarding your work with very little investment from their side.

Stackoverflow has gone through similar calcification - it's nearly impossible to contribute now, or build reputation as a new user, as posts get closed as duplicates or not-relevant.