Merry christmas!
I am happy to dispell your doubts once more.
Firstly, you are right, for food and small purchases the fees would be significant, as an example, a kilogram of maize flour here costs about 1$, so paying on chain is not a good idea.
For these cases people do not use on-chain transactions, they use instead wallets or exchanges like Binance, instead, which allow in-exchange transactions without fees. Binance is becoming quite popular here, so are other exchanges, people mostly are using these for those micro-payments you describe and (hopefully) the main stack stays in a non-custodial wallet.
See:
https://pay.binance.com/enMerry Christmas to you and your family!
And also Happy New Year - may it bring you and your family a solution to problems, prosperity, health and good luck!

Thanks for the answer ! And then for me the "arithmetic" component scared a little - it seems like you pay for food, and you pay even more for the commission. And the type of joint wholesale purchases - is this not practiced? You can also buy flour or some kind of products that are consumed regularly and in significant quantities in "small wholesale", saving on commission.