i tend to use my computers for at least two years, most for like 4 years ... and i always can play all games
at the end of the 4 years i sure have to lower settings on latest games but they still are playable and enjoyable
so your computer must be either really old (probably around 2006)
or your computer is only an older one that needs serious maintenance (clean the system, clean the fans, maybe clean OS installation, new drivers etc.)
And yes, you are right ... fun does not come from eye candy, sure! ... but it also not entirely depends on how smooth a game runs ...
For me it is like that:
50% Gameplay
20% Engine/Netcode optimizing
15% Graphics
15% Support
those are just my subjective values!
but you also have to accept that time moves on, so does the progress in computer engineering
why not use that progress? ... if you like computer games you have to invest in your hardware
every once in a while ... if i know i have to buy new hardware i save a couple of month for that ...
it is not that you need thousands of Euros/Dollars every year ... PC gaming is a very affordable
hobby if you not need state of the art hardware every 3 or 6 month, and for enjoyable gaming you dont need
state of the art hardware