If he has solid foundation on his finance portfolio now, by all mean just go ahead. If for me at year 28 yrs old with such income and no commitment i will try to make my portfolio rock solid first before enjoying the fruit.
Thing can go south and nobody can predict it in future so the foundation is needed to avoid any start from zero or worst negative situation if anything happen. Your friend is 28 yrs old and if that mishap happen on 38 yrs old which wipe off most of his fortune. That would be disastrous.