Bitcoin investment is voluntary and not by force. And all what one can do na to tell them di advantages and the disadvantages of the investment. And if the person like am, you go direct them to buy and send to their non custodial wallets. Short term investment should be in exchange while long term investment should be in self custodial wallet.
We never force anyone to do business so likewise with any investment. If you tell someone to invest in Bitcoin and the person loss funds, you will be the one go receive blame.