These literal 10 year olds running around doing all this stuff... Do Asagao's parents just give her their credit card?
Feel like this one would have worked perfectly fine if they were college age at least
It would've "worked" but it would have felt fundamentally different. Sasakana's works are often about the exploitation of children, how adults simultaneously view them as "pure and innocent" while wielding harsh punishment the moment they step out of line, and this one is no different. Note how the comments swing on a dime between over-the-top praise to bitter judgment (or that one even explicitly sexualizes Kaede).
It's obviously supposed to be disturbing that such young girls are engaging in this behavior. They were forced to grow up before they were ready due to their absent parents (presumably Asagao's are rich and give her a credit card as an excuse to not have to take care of her), but they lack both the emotional maturity and -- at least as importantly -- the social standing to properly deal with their situations. Instead of offering help, though, society objectifies them for entertainment. A lot of this you would lose if you aged up the characters.