Rylais also means you rely on your abilities whereas jax is 70%+ physical damage with a proper build.

"proper build"

There's no such thing as that.

There are more or less effective builds for certain goals.

And if I want Jax to deal more magic damage, I can build Rylai's on him.

Whether one might want to do that really depends on the situation.

There actually is such a thing, otherwise you could argue ATHENES GIVES CDR THEREFORE IT'S GOOD ON KAT.

No, under no circumstance is it ever.

It's not weather you want to deal more magic damage it's "how do I deal more damage PERIOD". There is no situation in which AP jax > AD jax in terms of the effective stats he can utilize. TF is a core for a reason, and it's not because of the 30ap.

His ap ratio are fairly subpar. Jax scales far better with AS and AD then AP.

For fun, yes, you can obviously play AP. but in terms of EFFICIENCY and EFFECTIVENESS ad is better

DOOOOOOOOOODGe!!!!!