By definition a Christian is someone who believes in Christ and Mormons do unequivocally. Though they are no more a cult than any other religion. Every denomination of every religion thinks every other denomination or religion is wrong and a cult, hence why religion does more harm than good in my opinion. 10 billion people, 10 billion religions. Except atheists and agnostics we are all on the same page, but that's not a "religion"

By definition, all religions are a cult. Usually the catholic grievance is about the adherence of the trinity.

a system of religious veneration and devotion directed towards a particular figure or object.

The definition of Christian is "one who believes in Christ" I'm aware that Christians don't want Mormons to be part of their in group, but they do believe in Christ and the Bible, so if you want them out you would have to change the fundamental definition of "Christianity". It's wild how many people don't understand the fundamental definitions of words that we all agree to use. I'm literally not asserting anything except that they believe in Christ, and religious people want to freak out about it and say no they don't? Great example of how religion is pernicious and divisive.