OP,

In 1.0 it was important to play on your class when solo but Jobs were more oriented to party play.

It still applies in 2.0, however, most overworld mobs are extremely chump meat, so there's not even a reason to jump back to class for solo play most the time.

Also, back before launch, Yoshi-P ALREADY stated that Jobs are meant to be better than classes in every way. You cannot compare classes in this game to the original jobs in XI. Because in XI all jobs were on the same level playing field where classes are below jobs. And I'm pretty sure if Yoshi-P had his way and he was really starting this game from scratch, he'd remove classes and have jobs only.