Ya'all can't really be trying to compare 1980s stats to 2000s stats straight-up.
First, he ignored that Lebron taking way more threes depresses his shooting average unfairly. Because of the threes, Lebron's TS% is actually 58.1%, well above Bird's 56.4%.
In '79-'80, when Bird came into the league, the average game had 220 possessions/game (counting shots and turnovers). By the time he retired in 1992 that had dropped to 210.
In '03-'04, when Lebron came into the league, the average game had 190 possessions/game. It dropped to 186 by '06 before rising to 197 now.
Bird's basically getting a 12% bump on every stat just because guys were running up and down the floor and letting the ball fly in the 1980s. The game was a lot more wide open.
By 100 possessions, the numbers are:
Lebron: 36.9 points, 9.7 boards, 9.4 assists, 2.3 steals, 1.1 blocks
Bird: 30.3 points, 12.5 boards, 7.9 assists, 2.1 steals, 1.0 blocks
Add in the better shooting, and Lebron kills Bird on the advanced stats.
PER: Lebron 27.7, Bird 23.5
Win shares/48: Lebron .240, Bird .203
BPM: Lebron 9.2, Bird 7.2
VORP: Lebron 108.6, Bird 79.7
The only thing Bird has is rebounding, and that was still an era where just being tall was enough to get you massive amounts of boards. People go on and on about all the "great big men" of that era, but that's because a 7' man with athleticism was automatically an NBA starter, and there were plenty of centers running around the same height as Bird/Lebron without anything else to commend them. The pool of big men available today is FAR greater than it was in 1979, and they are FAR more athletic and skilled. It's only that their relative competition and what is required of them has gotten far more difficult - you can't be a low-IQ, slow-footed guy hanging out around the basket all day anymore.