It’s not “wrong” per se. However, burial of the body is preferred. This is because our Lord was buried, and rose from the tomb. We will one day rise as well. Therefore, burial is symbolic of our belief in the bodily resurrection.
Burial has been the tradition of Christianity from the beginning, building on the tradition of the Jewish people.
In fact, the pagans cremated the remains of martyred Christians in order to desecrate them. It’s sort of a slap in the face to the martyrs to voluntarily be cremated.
Christians have always buried the dead. Pagans cremated their dead. And, the Freemasons are the ones who in modern times got secular legislation passed legalizing cremation. And, this was from a pagan, materialist perspective-- denying the afterlife and resurrection.
Because those seeking cremation were doing so for this reason, the Church’s canon law was revised to forbid cremation.
The current canon law allows for it. Cremation is not, in the modern day, always associated with denial of the Faith. Sometimes it is now due to space issues, cost, ecology, etc.
So, as long as the person does not desire to be cremated as a denial of the resurrection, they may be cremated. However, their ashes must be interred, not kept on the mantel by Uncle Bob nor scattered.
The Church has never taught that cremation is incompatible with the resurrection of the body. The reasons behind its prohibition had to do with ensuring people were not lured into heretical belief about the afterlife and resurrection.