There's only so low SE can stoop. They have no obligation to hand-hold those with an extreme lack of intelligence.

You have to do most dungeons at least once to progress the main story. That gives you plenty of practice on your main job.

If someone chooses not to do dungeons with their alt jobs, or otherwise practice their role, that's not SE's fault. People like the OP really have to stop blaming SE and other people rather than the bad players that only have themselves to blame.