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 ntbefore 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 comeadtes to investment.
OP's father is into investment already but the only difference is he prefer traditional one unlike crypto that is full of uncertainties and you might lose your money in just a quick time.
I think he might change his mind in the future but for now let him decide on his own because it's still useless if you keep convincing him but he shows no interest because he does'nt even know crypto that much. Just keep telling him all your acquired profits for him to realize how potential crypto is.