I think the point is that GTA3 would likely not exist the way it did without Shenmue. Shenmue was a life sim with a hyper interactive 3d world with tons of different gameplay mechanics, non-playable characters with schedules, day and night cycle. It had a hyper cinematic story with dynamic cutscenes (interactive cutscenes), 3d melee combat, just a ton of stuff that no one was really doing at the time.

The game itself left no impact on gamers because of how ‘weird’ it was, but devs completely changed the way they make games. GTA3 as an example.