Why Not Roman Catholicism? The Quadrinity and False Jesus

There are billions of human beings that are a part of the Roman Catholic Church. Millions of others are contemplating on joining the RCC this year, mainly because they believe that Roman Catholicism offers the closest option of being authentic Christianity. But, is that necessarily the case? Is Roman Catholicism a Christian entity OR does it promote heretical teaching at the most basic levels of who God is, who Jesus is, and a less than priestly leadership to make it something other than Christian?