I get what you're trying to get at here - but counterpoint: a lot of sites offer very long or infinitely scrolling pages. Getting rid of stuff you've scrolled past or wont scroll to for a while makes the page not a memory leak. So specifically for Discourse, New Reddit, Discord, Facebook, Twitter, Bluesky, and all those family of pages, if you do manage to succeed you will turn the page into a memory leak. And it's going to lag your renderer if those objects aren't unloaded.