Prohibition of goods on Hol HaMoed

Shalom Rabbi and happy holidays,
In Tractate Moed Katan it is stated: "Rava said: Any kind of prakamatiya is forbidden. Rav Yossi bar Avin said, and regarding the matter of loss, it is permitted ."
As far as I understand, when people say prakamatiya, they mean buying something in order to sell it at a profit. For example, if I see someone selling iPhone cases cheaply, and I think I can buy 100 of them and sell them at a profit after the festival, such a thing is forbidden, but buying an iPhone case for my own use, such a thing does not have the name prakamatiya at all. Where did all the prohibitions on goods that exist today, for example, regarding buying clothes, come from? After all, someone who buys clothes, even if not for the festival, does not buy them in order to sell them at a profit afterwards, but for personal use, and therefore it is not prakamatiya at all.