Yep, this serie was fated to be short, MC have no hurry whatsover in getting strong, he could and should grind at a steady pace, get stronger and then challenge higher fields, his skills and mana pool are good, but not that good, this is literally just rushing to his grave.
I would understand if he had got a death notice from the gang or something, but there is nothing, he is simply challenging places too hard for him without a thought.
And his overconfidence in his skills is pretty bad as he only understands them after using them.
Even the world building sucks, with monsters that don't use magic dropping magic books unrelated to them.