Quote: "...and I'm sure I could also point out examples of dead code."
But the only way admins could possibly differentiate between "dead code" and "valuable content" from years past would be to manually comb through some 2.7 million posts. Many of the most relevant results in most large programming forums, including Stack Overflow, are a decade old or beyond.
That said, programmatically it shouldn't be difficult for them to add an optional date filter on the full search page (e.g., "Last Month / Last Year / All Time") which would alleviate these concerns for anyone who wishes to only see the most current discussions, without preventing others from discovering old threads and content.
Quote: "These are all things that should be looked at every year or two and I'm guessing that not much has changed here since the start..."
The forum was revamped quite heavily a couple years back. There is an active thread for bug reports and requests at the link below, you may wish to suggest adding a date filter there.
https://forum.thegamecreators.com/thread/215506