I hope the author gets around to explaining why the MC is a fucking idiot sometime soon.
"I wanna be a merchant!"
MC is bad a business. To the point that even though he KNEW that trust was the most important thing for a merchant back in Chapter 2, he doesn't understand it 20 chapters later. Is NEVER looking for business opportunities beyond simple product wholesaling when he absolutely needs money. He could make bank as a delivery service for perishable goods, or even as a mass freighter. As was pointed out he could turn 19th century tech into a fucking gold mine by patenting or just selling the designs. Any tech that allows non-magic users to dupe useful magic effects; hand pump for water. wheellock fire starters, sodium lamps, the fucking steam engine, the paperclip and the safety pin, leaf-springs, coil springs, triple-beam balances, evaporative method to turn seawater into salt, modern farming practices to improve yields and revitalize worn-out soil...the opportunities are practically endless. But no, he just wants to crash the fucking pepper market to make a quick buck.
"I wanna be a hero!"
MC is bad at heroing. Has a bad temper when provoked. Lashes out at people who piss him off. Refuses to prevent the obvious villain from killing/having people killed, then doesn't actually kill anyone who deserves it. Tells the Goddess he intends to use his power to change the world, refuses to get involved in any meaningful way on solving the actual probelms. Starts a negative PR campaign against himself to force himself to worry about the impact his actions have on others rather than actually learning to think things through and control his temper. Runs away from his problems instead of facing them and dealing with the fallout of his actions.
"I wanna be an adventurer!"
MC is bad at adventuring. To the point that he leaves a fortune on the road fo others to pick up instead of taking a few minutes to collect it (he could have put ALL the goblin corpses in his void storage for later processing and disposal. This also allows him to prove he killed them. Refuses to use his power, skills and access to superior technology to do anything useful, like kill monsters and villains.
I like this manga, but the MC keeps getting stupider and stupider. Unless he was an absolute anti-social misanthrope or had anger management issues before he died (which would explain why he was doing temp work as a delivery driver at his age) none of this is explained by his previous character or background.