When you hear cryptocurrency is highly volatile, that picture(your post) is what they are trying to paint. It fluctuates easily thus the popular saying that says "cryptocurrency are very volatile, it can drop to 0 any day, invest only what you can afford to lose"
of course people should do that. not to invest with money that they still need for daily life. it will be bad for them if they not ready for loss. for me i better not invest in cryptocurrency if don't have free money