It's usually hard to persuade the older generation to invest it cryptocurrency and that is because most of them are not tech savvy and it is not good to invest your money in something you don't know. Try to enlighten them about the technology and how it is the future before you advise them to invest.
Why do anyone want to persuade anyone to invest in the cryptocurrency market, even if they are tech savvy you cannot persuade anyone to invest in something they have no interest as it will end up in a loss if they are not independent about how they can trade and book their profit and no one can trust a third party when it comes to investment.