The main problem is that he will still act the way he will act, and not how you will act. What may be successful for you may not be so for him in the end. He may delay, he may suddenly need money in the midst of a bear market, and any other events may occur that will lead to undesirable consequences. Therefore, he must make the decision himself. You can only tell more about bitcoin, its nature, its benefits, as well as the risks associated with it. If a friend makes a decision, you can help him do everything in the most secure way, tell him about the importance of the private key and the seed phrase. But deciding to invest for him or asking him to invest in bitcoin, in my opinion, is not worth it.