Mining as a student

Hello, I don't know if I am on the right subreddit for advice, and I am not even an amateur at mining crypto, just a begginer.

Point is, I want my theory approved/disproved: There are locations in my country where heat is not working during winter and it has become an reality and also a joke that students just leave their computers open 24/7 to mine crypto and to also generate some heat.

Let's say that the said energy is free (the student dorms are paid for the living, but not for the electricity), wouldn't it be a good strategy to grab any computer you have with a mediocre GPU, let it mine 24/7, make some amount of money, and with it later buy performant GPU's for mining, having a source of money that covers a little of the rent + the lacking heat?

(Ofc, I want more critic about the mining with mediocre GPU's part)