Simplified: If you can borrow 1 Million USD for 0% apr and earn 1000 USD with that, you have 1000 USD in profits.
Now change the apr to 5% and you are 49,000 USD in the red.
Fully agree. You can be lazy AF, as long as you get a few key assignments done or overfulfill them. Everybody will be like 'ooh, he so good' and forget that you don't do shit for 95% of the time.