While there are certainly some bonkers deviations at the level of theology (Mormonism theology tends to be childishly literal where it departs from Nicene Christianity, as it is at its heart an anti-intellectual and inherently out-group long-con), and of course there are the extra sacred texts and culty tendencies, Mormons view themselves as firmly within the Christian tradition, and they are culturally more in line than not with Christians than other Abrahamic adherents. I think it’s stretching to count them as an entirely different religion.