I've got 190 games in my Steam library and I've played 130 of them. That's still 60 I haven't touched yet, but that's definitely over half. I technically have far more Steam keys from various bundles, but if I wasn't interested in the game I never added it to my library. The keys just sit on Humble Bundle or elsewhere, collecting virtual dust.
I used to buy games on Steam during their winter or summer sales if they were cheap enough and I heard good things about them. Eventually I realized I was wasting money since I'd never get around to playing so many of them, so I started to only buy a few games during the sales and try to make sure I gave at least an hour or so to each one. During the last year or so I've now decided to not buy any games just because a sale is happening, and only buy a game if I REALLY want to play it.
I've also got 116 games on Epic, but there's a lot of overlap there. All but I believe two are free games (I bought Hades and Griftlands). That has far fewer actually played games. I've played 19 of the games I've got on Epic, but only actually played like 4 of them from there. The others are overlap games I've played either on Steam or on a console. There's also a lot that I'd probably never play, I just got them because they were free. Giving it a quick look over, I'd say of the 116 games I've got on Epic, 35-40 actually interest me in giving a try. Sort of reminds me of my early Steam days, just buying games cus they were REALLY cheap. At least I didn't pay anything for these ones, though.