It’s an interesting video, I suppose more so if you didn’t experience game history in real time like those of us who did. No one ever thought Half-Life looked real. But wow, if you experienced games starting with text only and colored squares like I did, each new capability was incredible.
In Zork, you were wondering around an entire dungeon, simulated in text. Anything was possible!
Then a game like Ultima VII came around. The world was so huge, and it felt like a whole world where I could do anything. It was to me how Skyrim was in its time.
Ultima Underworld (or Wolfenstein 3-D or Doom for most people) felt incredible because it was movement in a 3D space, but without step transitions like the earlier dungeon games. When I walk, I actually see my movement in real time!
Each step was bringing us closer and closer to reality, and when you get to a game like Half-Life, where it feels like a small section of a world was being faithfully simulated, it was incredible.