According to your description, why genealogy can be sold at will. Why can't patents, household registration books and ID cards be written casually? As a bystander, genealogy is a simple way to record a family's perfunctory offspring and continue the family. Its purpose is to let future generations know their elders and who their descendants are. Patents are products or technologies invented by individuals, and others cannot imitate them. Only the inventor permits and agrees to manufacture it, or buys its patent right, can it be manufactured and used, otherwise it will infringe the patent right. The household registration ID card is a specific record for everyone, and everyone is different. It is not allowed to write or alter casually. To sum up, genealogy can be sold, while patents, household registration books and identity cards are exclusive, and it is required that they should not be altered or written casually under any circumstances. Think for yourself, young man.
It's just a personal opinion, for reference only.