4th to 5th and then 5th to 6th in a close second. Original Xbox was able to do 1080i as well. So 360 was not the beginning of the HD era really.
I don't need to demonstrate 4th to 5th but 5th to 6th was still massive.
FF8 released the same year as Shenmue. 1999 It used pre-rendered backgrounds,had pixelated faces. Warping textures.
Shenmue was in real-time. Had lip-sync and physics. Individual fingers on hands. Manipulate objects in the wall or a table. So this is early 6th gen and late 5th gen which even then shows a massive leap. Not even fair to compare late 6th gen visuals tho.
Bite my shiny metal cockpit!