I have a similar problem. Not just with articles, but videos as well. I made it my goal this year to actually get through the backlog.
I started with videos, because that’s the easier one for me. I started pushing myself to go to my watch later list before the recommended feed. Between cleanup and watching stuff, I’ve knocked out about 300 videos. I have about 100 left.
I think the reading list will be harder, I’m thinking of unplugging my TV for a while to create space for it.
Form factor does matter. If you prefer books, exporting the articles, compiling them into book form, and having it printed up might help. It might be a bit of work and have some cost associated with it, but if that allows it to fit into your normal patterns, that might be what it takes.