LOL well knowing the end of humanity would be useful , tho why not just ask for lotto numbers/something like that/stock invest, other than giving the fortune teller a cut
imagine shutting down because it's too successful
I see it as a stereotype in manga and such tho i wonder how many ppl do go to off the street fortune telling as a serious thing rather than 'for fun', versus drawing charms/fortunes at like shinto shrines
tho if it's that successful Oni-san could've charged like 500 bucks a consultation or limit it to like "First 30 customers per hour" or so XD or some kinda group rate
(or with stuff like love, other than a serious decision like marriage or choosing between a love triangle i feel like most fortunetellers would be vaguely positive/tell you what you wanna hear)