How does engagement recency shape Gmail’s filtering?

Gmail particularly emphasizes engagement recency:

Recent positive interactions carry more weight than old ones. A user who opened your last three emails is predicted to want the next one.

Extended silence signals declining interest. A user who has not opened in six months may start seeing your mail in spam or Promotions.

Recency decay means you cannot rely on historical engagement indefinitely. Continuous engagement maintains placement.

This creates a virtuous or vicious cycle. Good placement enables engagement, which maintains placement. Spam placement prevents engagement, which worsens placement.

Your recent voyages matter more than your historical record. Fresh goodwill expires.