If we are going to be pedants I said the agi needed for max bonus was over 100, and you do get the bonus at 100+, even if at lvl 60 the bonus is the same as at 81 agi. At lower levels 81 isn't enough to cap out!
You said no bonus at all after 75, but as the maths shows there is a bonus after 75 for rogues as 81 is a higher number than 75
[You must be logged in to view images. Log in or Register.]. /pedantry
It's obvious to me that in classic devs did their best to make gear largely unimportant (tiny gains for +stats until the highest levels, pretty low AC hard caps going up to level 50, even the best ratio weapons before dragons (which weren't itemised at release) were not that much better than fine steel and so on). Unfortunately the Devs realised people were complete pixel addicts so tried to make stats rain from the dragons/planes/kunark onwards, even though the fundamental mechanics of the game were against this.