If you love someone, you desire their well-being. Not a problem. Therefore, you would do things to increase that wellbeing. Fine, but why not leave it there.
Love leads to good works and everyone is happy, but, No, Piper has to add something to the equation, which is not Biblical and is not right.
Enlightened self interest either means something or it does not. Ig it does not mean anything, then it must be dropped Occam’s razor so to speak. If it means something, if it adds to the command to Love your neighbor as yourself, then what is it? It says that we should love our neighbor, because we will receive a benefit from that love. In some sense that might be true, but it sounds too much like works righteousness to be taken seriously.
Christianity is not Judaism, although Piper seems to think they are very close. “Piper considers that Christians, living under the New Covenant, are not under the Old Covenant law but able to fulfill its intent through faith in Jesus Christ.[70][[71]]”(John Piper (theologian) - Wikipedia)
I will give you more than some citations. I will give you a whole book that started this whole sorry mess. * John Piper and Wayne Grudem (editors). Recovering Biblical Manhood and Womanhood (RBMW). Wheaton, Illinois: Crossway Books, 1991 and 2006.