In the US, people can get 100-500$ just by creating a new bank account and deposting money into it. Some people do that, but then immedietly remove the funds once the bonus is paid out.
In reality, yield farming is just that, except in crypto: https://www.reddit.com/r/churning/
It's people chasing bank / credit card marketing bonuses without really any thought of actually using those banks/credit cards in the long term.
This is the correct analogy.