You are begging the question, assuming what is not established.
What part of “unless you eat my flesh and drink my blood you have no life within you” don’t you get?
So to be consistent with your interpretation, you must hold that those who do not believe in the "Real Presence" cannot have life within them, thus they are spiritually dead, and cannot have eternal life. Affirm or deny, and your source for the veracity of this interpretation.
Your problem is that physically eating anything is not what Scripture teaches is the means by which man obtains life in himself, but by believing God's word, which the Lord explicitly taught man was to live by, (Mt. 4:4) and thus doing His will was His "meat." Thus.
As the living Father hath sent me, and I live by the Father: so he that eateth me, even he shall live by me. (John 6:57)
And thus souls were made alive within by believing the gospel, (Eph. 1:13; 2:1,5; Acts 15:7-9) and live by Christ by living according to His word.
And thus, since the Lord would "ascend up where he was before." and not be physically present again until His return, then He concluded,
It is the spirit that quickeneth; the flesh profiteth nothing: the words that I speak unto you, they are spirit, and they are life. (John 6:63)
If you want to ignore the metaphors John uses in most every chapter, and the metaphorical use of eating and drinking, then you can arrive at whatever conclusion you want . Including that of
in 2Sam. 23:15-17, wherein we read, “And David longed, and said, Oh that one would give me drink of the water of the well of Bethlehem, which is by the gate! And the three mighty men brake through the host of the Philistines, and drew water out of the well of Bethlehem, that was by the gate, and took it, and brought it to David: nevertheless he would not drink thereof, but poured it out unto the LORD. And he said, Be it far from me, O LORD, that I should do this: is not this the blood of the men that went in jeopardy of their lives? therefore he would not drink it. These things did these three mighty men.” Here, David equates the water obtained at the peril of the men's life (blood representing life: Lv. 17:11), with that of their lives themselves. In like use of metaphor, the Lord Jesus in the Lord's supper accounts is holding up bread and wine as a “picture”” of Himself, illustrating that just as such life physical giving substances could be broken and poured out, so would His body be “broken,” and His precious sinless blood be “poured out “ in offering a ransom for many (Mk. 10:45).
Other examples in which your literalism could be compelled include,
When the fearful Israelites exclaimed that the Promised Land was “a land that eateth up the inhabitants thereof;” or when Joshua exhorted the Israelites, “Only rebel not ye against the LORD, neither fear ye the people of the land; for they are bread for us” (Num. 13:32; 14:9), it is not to be supposed that the land or the Israelites would become cannibals. And when Jeremiah proclaims, Your words were found. and I ate them. and your word was to me the joy and rejoicing of my heart" (Jer. 15:16), or Ezekiel is told, "eat this scroll, and go, speak to the house of Israel" (Ezek. 3:1), or (in a phrase most similar to the Lord's supper) John is commanded, "Take the scroll ... Take it and eat it" (Rev. 10:8-9 ), then it is not speaking of literal eating. And it is certain that cannibalism was not looked upon favorably in Israel, and is only portrayed negatively, even metaphorically, as David declared, "When the wicked, even mine enemies and my foes, came upon me to eat up my flesh, they stumbled and fell." (Psa 27:2)
The problem then becomes that it's not the mass that causes the change but the faith of the person who believes that the change is happening.
If the change in the bread and the wine is as Catholics say, then it happens because it happens, independent of which setting it's in, which church.
It's going to happen independent of the faith of the people around because it would be a truth that stands independent of man, as the truths of Scripture are.
If the non-Catholic interpretation is correct, that the elements are simply bread and wine REPRESENTING Christ's body and blood, then all the hand waving and muttering of any priest is NOT going to change that.
So in essence, the Catholic ritual of the mass is not needed.