Yeah, but you should probably take a few minutes to understand what the stats mean.
First of all, Tim played for 19 years, and LeBron has played for 14. Those last 5 years for Duncan were after he had begun to decline with age, and also after Pop had begun to reduce his minutes per game. You can't throw all the "old-Duncan" stats in against LeBron, who hasn't reached that age yet. If you compare LeBron's Per-36 scoring to Tim's, for the first 14 seasons, you would find that Tim averaged around 21 PTS/36, and LeBron around 25 PTS/36. Not such a huge difference that I would disqualify Tim on that basis. How about you?
For about 10 years, Tim averaged something like 11 FTA/36 minutes. LeBron never averaged over 9. That stat alone tells you what they had to do to try and contain Tim. He drew a hard double team on virtually every play during his prime years. Tim also averaged almost 12 RB/36 in his prime years vs. 6.7 for LeBron. If you want to discount the importance of those things, fire away.
It's always hard to get a handle on individual defensive contribution through stats. People always focus on blocks, and Tim averaged about 3x as many blocks per 36 minutes as LeBron during those first 15 seasons. (Roughly 2.2 BLK for Tim vs. .7 BLK for LeBron.) But it goes WAY beyond that. LeBron is a very good defender. But Tim was a ing mountain in the middle. LeBron disrupts plays - Tim disrupted games on defense. Game plans.
Put it another way. Put a 25 year-old Tim Duncan on this team and tell me what you think it would look like. In case you've forgotten, Tim put up 25.5 PTS, 12.7 REB, 3.7 AST, and 2.5 BLK. He was too much for any one player to handle on the offensive end, and he was a nightmare for other teams on the defensive end.
LeBron is a GREAT individual player. But nobody post-Jordan has done as much to make his TEAM a Championship contender as Timmy. So I guess GOAT depends a lot on how you measure greatness.