Trading psychology, Emotional control and all aspects of trading to attract the life that you want.
You're right.
The way OP is saying it make it look like anyone could do it. The truth is, you need money to buy decent PC. You can't efficiently trade by using your phone.
You also need some money to start. Trading with $100 will not be very successful since beginner traders often are at a loss and even if they can earn some money 1 month they will probably lose some the next one.
It also requires some basic knowledge and psychical predisposition to trade. The more scared you are of losing money the worse you will perform. You need to be calm and calculated.
If any of you want to be a trader, especially in crypto, be aware that more than 80% of traders lose money. If you're at 0 profit after a month of trading you're doing better than the majority!