But the problem with that approach is that people tend to revive zombie threads. I would estimate that <1% of threads actually have any useful discussion after 10 years, the rest is bumping zombie threads.
In any case, I’ve never experienced reviving old threads to be a significant issue, or to happen inappropriately to any significant degree.
I realize that where i am enthusiastic about older things, cars/bikes/tech/languages, you probably like new stuff. I hope you realize that most of the zombie revivalists agree with me. Most of the time we are looking for a new solution to an old problem, which is the definition of progress. Locking threads after 6 months (thanks Reddit) or berating someone who want to revive an old topic, cripples progress.
What we need are search engines to offer an opt-in view or keyword which prioritizes this genre of valuable older evergrowing content. Perhaps Brave Goggles can be adapted to this purpose, using HN reposts and other signals of longevity.