I have over 800 games in my Steam Library now. Somewhere in between 100-200 of those are likely from you making posts that something was on Steam for free. Most of everything else was wishlisted and bought on sale. Damn near all of them have never even been downloaded, I doubt if I have even played 20 of these games.

Meanwhile, I have 2k hours into Rust (had to stop playing that one though... It became a problem.) and a few hundred in a handful of others. The other 400 or so games, yeah... I haven't played most of them.