source engine games have held up so well! they definitely look lower poly / lower texture detail compared to new games, but the lighting is almost entirely ray-traced. It's precomputed, which means nearly everything needs to be static. In the time since then, a lot of graphical advancement has been in the direction of replicating ray-traced lighting but in real time. So lights and the environment can't move much, but it looks fantastic even by modern standards and runs on a potato. Great tradeoff for that type of game imo. valve's art direction at the time was peak, too, and they made very good use of an incredibly limited lighting engine. so I think all those games will hold up for a long, long while.

Titanfall 2 (same engine!) still looks on par with shit coming out now, and it's not old old but it is almost a decade old. (sorry)