If I might be just a little bit snarky, in my experience the problem is not at all the level of friction in finding and organizing content. The main problem is that people put more minutes of stuff into their backlog "for later reading" than they take out. Every day the backlog grows, because every day there is more interesting stuff published and added to the backlog.
Apart from regularly declaring backlog bankruptcy, the only way out of this is to spend more time reading/listening and less time adding stuff to the backlog. No amount of optimizing the organisation of the backlog will help if you just keep going deeper and deeper into debt.
For me these kind of things aren't supposed to be "backlog", but more "library of things I'm aware exist". If I save/bookmark a few resources on X, that doesn't mean I intend to read all of them, but that I think if I need resources about X, those could be useful.
Pocket is great for this. Just hit that pocket icon and close the tab. Now it's gone from your life forever. I just hope that the browser extension will keep working even if the service closes down, so I can keep putting things into Pocket and never ever read them.
That is, until you collect a few dozen thousand pocket bookmarks at which point you are at "there was this thing... how was it called?... have I saved it to pocket? Maybe I did... or not?"
I think it is fundamentally the emotional problem of FOMO. The way you solve that issue is by understanding clearly the tradeoffs. Better organization and an ever growing backlog sheds light on how much you can actually consume versus how much you must miss out on. The lack of knowledge regarding this is the source of the pain point.
My idea for solving this revolves around the same concept as the "Snooze" feature in Gmail. When saving, estimate the timeframe you hope to read it: 1 day, 1 week, 1 month, 6 months, "someday". Then condition yourself to read what's in your daily inbox, as opposed to chasing the shiny thing.
Thinking about it as 'backlog', that is 'something you are supposed to consume and use later' is mistaken I think.
When you think about it as 'external brain' it becomes much more reasonable thing to do. I'm not going to remember everything I read anyway - but I can suspect some content, that I don't care about consuming now (and possibly ever) MAY be useful at some point in the future in some way, and I'd like to skip few steps of consumption (like reading the whole thing, watching whole movie) and use it anyway (have a conclusion, post a gif reaction). It's still transhumanist sci-fi, but it looks doable now.
Apart from regularly declaring backlog bankruptcy, the only way out of this is to spend more time reading/listening and less time adding stuff to the backlog. No amount of optimizing the organisation of the backlog will help if you just keep going deeper and deeper into debt.