I’ve never seen defenders back off Penny and dare him to shoot like players have done to Lebron.
I doubt you actually watched much Penny at all. He was a poor 3pt shooter and a decent midrange shooter. Teams backed off of Bron because they were playing a zone defense and had to pick their poison - the fact that LeBron won titles on the strength of his shooting should tell you something. Even during his worst shooting stage (2003-2012) he was a better 3pt shooter than Penny was, and the evolved version from 2012-2020 is a class ahead.
Lebron can somewhat shoot now. But he ain’t a catch and shoot or spot up jumpshooter by any means
LeBron is great on catch-and-shoot and spot-up threes, he just doesn't get them very often because he gets all the defensive attention and has rarely had a talented shot creator on the squad. One of the reason he shot 41% from three in 2013 was because Wade was setting him up for good looks.
That doesn't make him an elite shooter, but he has clearly become a good shooter, and he's better than Penny ever was.
Lebron has never amazed me with an array of post moves either
And yet he's been one of the most effective post players in the NBA since 2012. He doesn't go to it much because other scoring opportunities are even more effective (which is why the entire NBA has reduced post play to a large degree), but when he does do it in specific situations he does extremely well. He has a great drop step, spin moves to both sides, fadeaways to both sides, can slip a layup under a player faked into the air, hits both hooks and fingerrolls with both hands, pulls his defender into the middle and then pops a little one-handed teardrop from close range, and sets those up with very good head and shoulder fakes, and is one of the best passers out of the post in the NBA.
www.si.com/nba/2014/03/19/nba-post-players-dirk-nowitzki-al-jefferson-lebron-james
LeBron James, Low-Post Beast
As far back as the 2012 ECF Game 6 LeBron was winning huge games off the strength of his post play. Here's some early Bron post dominance, when he wasn't smooth with it but still effective due to his strength, speed, IQ, and ambidexterity.
As time went on he developed more impressive and smoother moves, built off of shyt he learned from Hakeem and Kobe among others: