I have a huge number also. And I've played a small fraction. For example, Stellaris - I've got almost 900 hours played. Against The Storm is running a close second. Some other games, less than an hour. If it is 99 cents, I'm probably going to get it if it looks somewhat similar to anything I enjoy.

If you check out Humble Bundle, you can find bundles of games where you get 20-30 games for around $20. Many of them are charity bundles, like one I got to help people in the Turkey/Syria area affected by the 2023 earthquake. Those bundles mostly consist of keys redeemed on the Steam platform. I don't play first-person-shooters, so those are going to sit in my library unplayed & uninstalled.

Let's say you on average manage to find 8 hours a week in a normal week playing videogames. A decent bit, no doubt, but not too crazy for someone who would consider themselves a "gamer".

You do that like 50 weeks a year. That's ~400 hours a year. 2,500 / 400 = 6.25 years.

My Steam account is 20 years old. Even if we doubled it to 5,000 hours, that's 250 hours a year. Roughly 5 hours a week on average.

That said, a lot of people just end up owning a lot of games on Steam through sales even though they may never play them or only put a few hours in them. I've got >200 games and yet over half have <2 hours of play time. A ton I've never installed, they just came bundled in sales with other games I did actually want. When you can buy a whole publisher's collection of games for like $20 on some crazy sale why not?