Jarvan doesn't get free Lifesteal and Spellvamp.
Jarvan's 10% current life damage has a 6 second CD at level 13. He might get a single proc off in one fight. It also has a cap on damage.
Jarvan gets a shield that has no scaling minus enemies being within 300 range. Usually, that's 2 or 3.
Jarvan's knockup: width: 180. The way I think that works is that it's actually 90 units to each side from the CENTER of his hitbox.
Jarvan does not have an 1100 range gapcloser. If you want to factor in all mobility.. Lee: 1800. J: 1410.
You can literally walk through Jarvans terrain sometimes. That's still a bug and it still exists.
Lee gives his team a 4v5 advantage while Jarvan usually dies if he runs off to the enemies backline.
Let us not forget that Jarvan has map specific nerfs in that his Armour shred is worse and his passive takes longer to 'charge' up while lee has no map specific changes.
The most important thing: LEE HAS NO COSTS. 50/30 50/30 50/30 0. That's a ton of energy considering he gains back 10 a second and also regenerates 30 everytime he uses 2 AAs after a single ability, so his costs are effectivly 20/0 20/0 20/0 -30. He spends a solid 30 energy on his entire kit not including natural energy regen.
Jarvan's ult CD at level 16: 90 seconds. Lee sins ult cooldown at level 6: 90 seconds, at 16: 60. Both usually build some CDR, so might as well go with 40%. 90 becomes 54 while 60 becomes 36.
Lee sins cooldowns are pretty much lower across the board until late game. Then Jarvan gets a solid 1 second faster Q and 2 seconds faster on his W.
Jarvan has higher base magic damage on his E, but guess what? Lee's E scales with AD! 100% of his bonus AD to be exact.
Lee's ult also sends the poor target 1200 units away. A pretty massive distance. It also deal 200/400/600 +200% Bonus AD.
Jarvan's ult locks you into a cage match that, guess what? You just got out of because there is SO MUCH MOBILITY IN THIS GAME IT'S DISGUSTING! It also does 200/325/450 +150% bonus AD
I've compared almost everything minus base stats.