The whole leveling experience of a new player... is this?

[Pintsized]

I have logged over 50+ hours of constant game play time (after removing the afk hours).

Sounds like you're ignoring basic content, to be honest.

I've leveled several characters to cap and none of them struggled to gain XP on their first job (except for the late 40s as Niwashi just noted), they simply did the main story, sidequests, hunting logs, GC logs and an occasional FATE as they found them.

Sure, leveling a second job does require a grind but I've never had problems leveling the first.