Sonata VS Concerto

Was having dinner with my friend from China last Saturday, after his concert.

Not very sure how we started it, but we ended up argued about this. He was saying that Concerto is a more advance and at a higher level of playing compare to Sonata.

For me, i never like to think like this. Therefore i was trying to tell him that we should never compare like this. We cant just say the piece is more challenging just because it is a Concerto. And it also doesnt means that the Sonata is much easier, and technically less demand than Concerto.

He was mad at me when i said it, and yet he keep insist that it should be that way. Then he throw me this example, like why all the International competition always have the Concerto as the final piece? Oh gosh... how can this be an example... Final doesnt means ALL for the competition. Yet, he came out with another example, saying why student always try to play Sonata before Concerto.

I just don't like to think like this, and we shouldn't have compare music like this.