hello @reeta0119,
cryptocoins are a highly volatile digital asset, this from my point of view is quite good if we consider that almost nowhere else can you earn quickly, the only problem I see with coins is that people tend to listen to two or three yellow news to base their opinions, blockchain technology is a difficult thing to understand and that is why people develop myths that they then assume as truth, I recommend you don't spend your time to convince him as he has no ability to evaluate the benefits of blockchain.