Jarven has tank engage/CC, bruiser base damage, and assassin scaling
I will get downvoted for this but it's true and it's why he's always in pro play.
You'd think a guy who can knock up multiple enemies, shield himself + slow nearby enemies, and hard engage with a mobility limiting ring would be a hardcore tank, not to mention his little utility things like armor reduction and attack speed banner. But his numbers are tuned in an attempt to make him a bruiser and the result is this disgusting monster who dunks squishies to hell with assassin level burst and one of the best hard engages in the game.
When he came out he was a tank, and back then every champion had good scaling, but defensive items were really strong so building a tank like an assassin was just a yolo queue gimmick. After nerfing defensive items, champs like J4 started going for burst builds because why not? Nobody can itemize against it besides other tanks and bruisers. In most cases Riot tuned down tanks offensive scaling (AP Alistar is the best example) but for some reason with J4 they tried to keep his huge AD scaling and base damage. They reduced the width of his knock up but otherwise they left his amazing hard engage intact.
I've held this opinion about J4 for years but I was just talking to somebody and got reminded of it so I feel like sharing it with boards.
I guess it's one of those things where they want big flashy LCS plays to hype up the game and J4's ult is really epic (DEMACIA!!) so he should 1 shot people so commentators can scream into the mic every time.

's mobility ain't that high compared to other divers but they have high sustain like some juggs have.
increases darius's max heal while renekton's cap is just reached faster. So yeah juggs to have better baseline sustain in the mid to late game.
? She is more DPS than burst focused and she is a diver. Same with
with his low CD abilities.
will grab you and stay on you till you die before you do anything. J4 on the other hand is hard to catch! lastly he does a lot of damage with his ult because the utility of his ult is rather weak. Most used champions can escape his ult if they don't have flash up or are in a position were being stuck in his ult is not threatening as he is diving the team J4 will be on their turf not the other way around. This why riot made his ult hurt so much, other wise it would be entirely pointless and useless.
, that mess is what happens when riot trys to make a tank thats not just hp and ap ratios.