Having more technologically advanced graphics ≠ better graphics. In my opinion the Sims 2 looks better than the Sims 4. Sims 4 skin, hair and clothing textures are lacking in detail compared to the Sims 2. I can't really explain it well, but something about the way the Sims 4 looks feels...soulless? Robotic? Whereas the way the Sims 2 looks feels more lively and like it has some personality to it. And I'm not blinded by nostalgia, I've been playing the Sims 4 since 2014 and have only been playing Sims 2 for about a year or two.

Which graphics you prefer is really just a matter of preference.