That the Tom Riddle of this universe gave up a useful bargaining chip to save Beatrice Potter’s life for no reward beggared belief. Not only did he sacrifice useful blackmail against Abraxus Malfoy for no gain, but he also actively set his own advancement back. The longer the current Lord and Lady Potter lived, the longer it’d take Tom and Harry to become the Lords Potter. Tom Riddle had wasted a golden opportunity to nullify a barrier to his advancement.