It's not about changing them because they're old, but rather because they can't fit your needs anymore.
If you are satisfied with what you currently have, don't feel the urge of maxing out every possible detail and want just to play the just released game because it looks fun, a console will be a much better investment for you.
True, those components are relatively old for any present and future game, but retrogaming is still a very viable (and pretty fun too) option. DOS games can still provide a lot of fun and can literally run on any hardware, provided you got a dosbox installed and configured.
If you, however, want to play games and max out their graphics, then yes, a change will be needed.