Why is Irelia considered good when Jax isn't?

Cause Irelia is a bullshit champion who has an amazing passive, can farm extremely easily, duel stupidly well, has a 2 second stun when you are somehow losing a trade and a 2 second slow when you inevitably win the trade, and on hit true damage.

Did I mention she also has 2 built in heals?

Because Jax has lower base armor and hp than most melee champions and even some ranged ones

He's trash tier atm

He has the potential to be a lot tanker but only during his R, and he loses all lanes for it while Irelia has no bad lanes and has WAY better base Hp and armor

Irelia's tankier, and farms much much better early.

Why are people all of a sudden so into the eggplant man?

On top of what everyone else has already said, I will add that making a comeback as Irelia is so easy when you get Trinity Force. The majority of top laners get punished for the rest of the game for preforming badly during the laning phase, she does not.

Irelia is strong in all parts of the game. Jax suffers an extremely weak early game for a powerful late game. Irelia gets her powerspike earlier and is still relevant late game.