I do, eventually, move books out of my TBR and back into "Not Read" status, or worse, "Not Interested" in Calibre. But it appears to happen much slower than the lust for new. And, I admit, I'm sometimes guilty of "retail therapy" in book buying. Which usually results in several books I 'ought' to read, and one or two I might actually read.
I've found myself doing many more re-reads in the last 18 months. Always of old favourites, and I often find I re-discover them anew. OTOH, it doesn't always work out, as with the recent re-read of the original Valdemar Arrow books from Mercedes Lackey. I succumbed to an omnibus re-issue and then read them almost immediately. The first was good, the second was awful, and the third OK. But when I was done, I felt like it had mostly been a waste of time. (I'll report on them in a different thread.) The real problem, however, is that I bought that 3 book omnibus,
and three others! I'm now not at all likely to read the others.