My sister and I had an argument more than once about the veneration of Mary. It always turns into an argument regardless of how gingerly I approach the subject because she venerates Mary so well and so completely that she cannot fathom the great power that comes from the shed blood of Christ. It just dawned on me that maybe she feels she receives her 'empowerment' from Mary? I find that just backwards.
The Catholic church does teach about the shed blood of Christ, but somehow, in my experience, it does not seem to
focus on that power. At least that is my experience in the RCC church I grew up in.
Back to my sister...she venerates Mary so much that she has a "shrine" in her home to Mary in the form of one of these water fountains, with a statute of Mary beside it on a pedestal, with piles and piles of pine cones around the statute. When I try to tell her about the history of why Catholics venerate her so much, I can see the brick wall being built rapidly like the Bugs Bunny cartoons where ol Bugsy happens to have brick and mortar nearby and rapidly builds the wall before his enemy runs into it. (lol)
The plain fact is that the RCC system is a universal system and it was put into place by Rome so that the people can worship whatever gods ( RCC saints) they wish to pray to.
Side note: Someone once made a statement to me that the Christians back in that day were not persecuted for worshiping Christ, but that they were persecuted because they refused to worship and recognize any of the other little dieties
along with Christ. People were supposed to have given the same worship to other people's gods. Sort of like today...we are not supposed to criticize Mohammed, Hindu, Buddism and all the other various idols, but to revere them along with Christ. That is what the Masons do I am told.

....ain't gonna happen with me.
Ancient religions worshiped the madonna and child. Perhaps Mary morphed into just another name for the entity of Diana or Ashtaroth /Astarte?
Ashtaroth in ancient times was the "Queen of Heaven" in
Jeremiah 7:17 ¶Seest thou not what they do in the cities of Judah and in the streets of Jerusalem?
18 The children gather wood, and the fathers kindle the fire, and the women knead their dough, to make cakes to the
queen of heaven, and to pour out drink offerings unto other gods, that they may provoke me to anger. This is one type of the pagan worship that God hated so much, especially since the people He loved so much descended out of Abraham's loins and because of the promise He made to Abraham.
The RCC considers Mary to be the "queen of heaven" and my sister told me "absolutely, she is". I take that thought process very seriously.
In all fairness to Mary, I think that she would be appalled if she were walking this earth today to know how many people venerate her. I do not believe that she would want this celebrity status because she was a very humble woman who loved, worshipped and feared God.
So...although I feel spiritually wounded by both organized church systems I was worshiping in, I could never return to the RCC because of the Mary veneration, as well as the praying to the other "saints". I consider it to be idol worship. There is only one man...that man Jesus Christ of whom I could ever worship because he is God Incarnate and there are no other gods before or alongside my Creator.
And although I was hurt much, much worse by some people in the Spirit-filled
Apostolic movement, it would be the only organized church system I would even consider returning to. I cannot change OPs from within. I tried that once not realizing that they consider that to be usurping man's authority and will not consider going into that battle again. But if there was an OP church in my area out there who actually does not take the clergy/laity paradigm to the extreme that many, but not all UPC churches do, and more to the equal brotherhood as Jesus told his disciples to do, then I would run to it for worshipping of my Jesus in a heartbeat! There just are not any in my region.
And lastly, some here would probably stone me to death, but I would consider trinitarian churches to worship Christ in because what drew me to the OP churches in the beginning was the love of Christ that I felt among the brothers and sisters there. People change...God does not. If that same love is to be found in a trinny church, I would go and worship Christ. Until then...my home is my closet. My fellow outcasts who are likewise believers are my fellowship.