We agree Rev makes many symbolic points. Having said that, your reply leaves no room for any literal interpretations.
The OP made no reference to 666. So, I'll leave that rabbit hole for another discussion thread.
Literal vs symbolic scripture's examples:
This verse ALL literal
Rev 1:7 Behold, he cometh with clouds; & every eye shall see him, & they also which pierced him: & all kindreds of the earth shall wail because of him. Even so, Amen
This verse symbolic
Rev 1:14 His head and his hairs were white like wool, as white as snow; and his eyes were as a flame of fire;
(NOTE: NOT wool or snow or a flame. BUT: "like wool" "as snow" "as a flame". We must pay close attention, CONTEXT is always KEY.
Rev text often announces symbolism with phrases like: sign, like or as, I saw, having the appearance of, which represents or which is...
Examples: Rev 12:1: "A great sign appeared in heave", "a woman". Rev 13:2: The beast "was like" "a leopard". When text signals a symbol we should interpret symbolically.
In Rev, #'s tied to counts of people or time are consistently literal.
Examples: 7 churches, 7 seals, 7 trumpets, 7 bowls, 42 months, 1,260 days, 12 TRIBES, 12K from each tribe etc...
Rev cites literal places. Examples: Jerusalem, Euphrates, Armageddon, Patmos, Zion etc. Unless symbolic its noted. Example: Rev 11:8. "spiritually" called Sodom & Egypt.
When Rev cites earthly judgments, they are literal. Examples: earthquakes literal, darkness literal, famine literal, plagues literal, war literal etc...
When symbolic is signaled, interpret symbolically. If not, interpret literally.
How this applies to the 144k. John gives numbers → literal tribes, literal names, literal genealogical bloodline categories. When no symbolic signal given → interpret literally!
So again I submit the 144k mentioned in Rev 7 & 14 are literal OT Israelites. Men redeemed from the earth, a firstfruits/resurrection wave soul harvest offering made unto The Father & Son. Amen