"I have a trash skill. It heats things up less than a Microwave."
"Haha, I'm using my trash skill to make a cannon that shoots a projectile at high speeds with just pressure!"
So, wait, is it weaker than a microwave, or is it stronger than a pressure cooker? Because if he can make a steam cannon that quickly, isn't that kind of an intense heat change?
It's either an OP talent that people just never bothered cultivating, or he's got a talent that looks like a trash-tier talent, but is stronger.