Either you spend too much time looking for new things to add to the queue, too little time processing the queue, both of the above, or you cast too wide a net for what you might possibly read one day.
If you can knock one off every day you've got two and a half year's worth of items in your queue that you haven't even looked at yet? This is on top of all the things you are already consuming as part of your work or for leisure and at the same time assuming you don't add more things to the queue.
That's madness, and I don't care if you call me judgmental.
It is unreasonable to have that many items in your to-read queue. Stop adding things or start reading things faster (or better yet, both!)
And oh I sure have looked at them, but havent grokked them. Once I do that or I come back to them again and again then they get bumped to a bookmark. Lets say they are part of my job and leisure, sometimes I lose track which is which.
Think generational garbage collection. Tabs and bookmarks are the different generations. I still like tabs better as they preserve more context.
Btw some jobs require more researching than others. Regarding "madness" yes I agree.