Read Genesis and read about the 7 headed beast and notice the difference. Read Revelation 17 then read Genesis 1-11. Not comparable. Anyone who says we pick and choose what’s literal and what’s symbolic, basing their claim on comparisons of Genesis and Revelation, is ignorant or dishonest.
Not comparable? How can you tell? They had different authors. Perhaps the symbolism in Genesis is masked to you by the author’s style.