The analogy works if you know the comparison.
I mean, first, Diablo 2 did come out in 2000, 13 years before Path of Exile.
But also Path of Exile is maybe the game that has received the most updates and content of any game in existence (No Man's Sky looks stingy compared to Path of Exile, imo). It receives a small expansion's worth of content every ~4 months. Path of Exile in 2026 is an entirely different experience from Path of Exile in 2013.
I absolutely would not play the 2013 version today (and also am unable to because it's a live service game).
The better comparison would be Path of Exile 2, which came out last year or comes out later this year depending on your perspective on Early Access games, but it's less a 1:1 evolution of Diablo 2 and more its own thing.
I also like old games, but I grew up in the D2 era, so they hold nostalgia factor for me. There will always be games that stand out as classics, like Diablo 2 and Super Mario 64, but not many people play them who didn't already play them during their era, and even fewer people are going out of their way to play Titan Quest or Gex 64 for the first time in 2026.
Games do age, more so than books and movies, imo, because it's a younger medium and the technology keeps evolving.
As an aside, I also think entertainment industries are not saturated. I'm always hunting for recommendations that hit just the right spot, and so much is a miss for me. I'd love if there were 10 Path of Exiles to choose from, I'd play them all. (Hell, I'd be happy with just one quality Pokémon game...)