Old content doesn't just disappear; it lingers in search caches and archives,...

https://stateofseo.com/should-i-301-redirect-old-urls-or-leave-a-404-the-reality-of-content-decay/

Old content doesn't just disappear; it lingers in search caches and archives, often dragging down your site’s authority. When legacy pages resurface, they create broken user journeys and dilute your SEO signals