Jarvan unlike other champions has to fully commit to something. And his kit is not nearly overloaded.
His standard used to do something other than be a marker for Q, it used to give a sizeable attackspeed buff and armor to your team, but they took all that away.
He has to COMMIT. If he jumps away, hes not coming back or else hes not going to have tools to do so.
EQ is highly telegraphed and easily dodgeable, but outside of that all he has is auto attacks. Any sort of mobility, cc, or knockbacks and hes just so sad. If you can dodge the EQ combo and just dash away, he will walk away in tears every time.
Also it does not give a shitload of attack speed. His attack speed base is low to compensate, and it gives 18% on active max last time i checked.