Why can't my graphics card run games?

I have a Nvidia GeForce GTX 1660. I can't seem to run some modern games well. Last time I checked 1660 GB was a pretty big number (bigger number = more powerful). I think I got a couple more years with this graphics card. I heard their has been new releases on graphic cards. Any fixes I can do to my pc?

Games that can run well: OpenTTD.

Games that can't run well: Helldivers, The Finals, and some other games.