I'm getting a little tired of this "class lottery" concept.
1. If classes are actually assigned by gods, what do we know about said gods? Are they fair and benevolent? Or whimsical and possibly malicious? The former would mean that even a "jobless" class has meaning. The latter means that you can't blame someone for the random whims of an unreliable god.
2. Assuming the class is random and you can't build skills (real skills, not game-like instant skills) out of your class, personality matching can go horribly wrong. What if a "hero" or "knight" class are assigned to a coward? What if a noble who learned from childhood how to manage a territory gets a farmer class? It invalidates all you do in your childhood, which you might as well spend fooling around since anything you train for or learn has a high chance of being wasted. You can't build a society with such a worthless foundation.
Overall, it's just a cheap premise to get the MC dismissed from his family or party before he realizes his real potential.
"Skill lottery" is a little better (not by much but still) as you might get something you can apply in several ways, and doesn't prevent you from building an unrelated skillset. Your whole job being determined by chance, particularly when it's so late in life, is just plain stupid.
It can still get decent past the prologue section, but I'm starting with a bad feeling about this.