Brother David, precisely that Blood of Jesus is on the Altar! It takes deep faith to be able to recognize it. The Lord said clearly
"My Flesh is food indeed, and My Blood is drink indeed" and people left Him because they couldn't accept it; notice nobody left Him when He said
"My food is to do the Will of the Father"; everyone understood He meant He derives strength from doing His Father's Will. But here we Christians are supposed to derive our strength from eating His Flesh and drinking His Blood in Holy Communion.
"Unless you eat My Flesh and drink My Blood, you will not have life in you". We will be weak if we do not subsist on the Body and Blood of Jesus. The Apostles' responded with pure faith.
"Lord to whom shall we go? You have the words of Eternal Life". The Apostles believed, the others walked away. That's why the 12 Apostles were invited to the Lord's Last Supper, and the others weren't. If you disagree, that's ok. But as others said, in that case, Holy Communion will indeed become only symbolic for you. The Apostolic Churches, Catholic, Orthodox and others, pray in the Liturgy for the Bread and the Wine to be changed and transformed into the Lord's Body and Blood before partaking.
This practice was handed down by the Apostles. See for e.g. the Liturgy of St. James, Bishop of Jerusalem, one of the 12 Apostles, which is still used in the Orthodox Church:
https://www.newadvent.org/fathers/0717.htm The Apostles clearly believed in the Real Presence.
We can discuss Mother Mary in another thread. In my opinion, Rev 12:1 shows God has honored Mother Mary, and She is our Queen and Mother (Jn 19:26; Rev 12:17), and it is a Biblical Commandment to honor one's Mother. Mary is not worshipped, but only honored.