The most obvious historical evidence of the Apostasy is the clear absence of the institution of the Twelve Apostles; and the (admitted) lack of ability by the church(es) to receive revelation leading to an open canon of scripture. The institution of the Twelve Apostles was never intended to be done away with. That is evidenced by the fact that in ancient times the council of the Twelve was preserved intact, so that if one of the Apostles died, another was chosen to succeed him. They formed the governing council of the Church, so that when a serious doctrinal or other issue arose in the church, it was brought before that council to be resolved, such as the question of the circumcision of the Gentiles for example. The absence of that council is one indication of the Apostasy. Another indicator is the inability of the church to add to the canon of scripture. While the Apostles were alive, they had the ability to receive revelation to guide the church, and to add to the scriptural canon. Doesn’t the Catholic Church claim that the canon is closed? That is another unmistakable indication of the Apostasy. None of this means that the Catholic Church became evil, or lost its legitimacy completely. It simply means that the authority was lost, which at some point needed to be restored. Here is a relevant quote from my previous post that I had referred you to:
That is a prophecy the fulfillment of which is indicated by what I have said above. “Having a form of godliness, but denying the power thereof:” means that they have the appearance of religiosity, but last the power of it, which is the ability to commune directly with God, and lead the church by revelation from God, as it was in the days of the Apostles, rather than by the wisdom of men. That is the condition of the Christian world (of all churches except LDS) today. That is the unmistakable evidence of the Apostasy.