I wishlist every game that looks like it has potential; check it every couple weeks to see if there's any 90% off deals. Pretty much don't bat an eye at anything below that.
I have that disabled or blocked. I don't check my email all that often, and most of the alerts I did get were below the purchase-worthy discount, so it wound up just being a lot of spam.
You can't possibly have an interest over so many games, it's not practical either. Even if you finish 100 games every year 2000 games would take 20 years.
To be honest, I'd probably call it "awesome" and be a bit envious. That must pretty much be a state where whatever mood you're in, there's always going to be something you want to play, like someone with an amazing collection of vinyl records, or bookcases full of literature & poetry.
Those are some pretty big numbers on hours played too, so it's not like you've just played each thing for an hour and then chucked it.
I only feel mine's out of control because of the relatively small amount of time I have to play these days, and the amount of unplayed games - I can play a new game every week for about three years, but actually I just stick another ten hours into "Crusader Truck Manager Fortress Rally Tactics III", on average.
I use isthereanydeal for buying any game and my list is HUGE. I don't buy anything until it's massively discounted but my library is way bigger than anyone I know because they buy everything for $60+.
About 20 something games. I usually go through whenever I add new things and delete things I'm not interested in anymore. Most of my wishlist is either early access stuff I'm watching reviews on, or stuff not out yet.
Same, if I don't want it when it's 5 bucks, I won't want it when it's 30. If I for some reason change my mind, then I'll just go back and find it again.
Are you trying to wishlist the whole platform, I'm at just over 300 but that's really pushing the wishlist (It would be larger if they had things like Movies that you could purchase on the platform)