The symbolism was used in other places of prophetic and apocalyptic literature. The only question is why it’s gotten so badly misinterpreted.
I find revelation and prophecy to be extremely literal. The main reason that it is often drifts into symbolic interpretation is an attempt to make it fit a theme instead of letting it be what it is, exegesis vs isogeses.
In the case of preterism, having to fit it in the past puts a strong bias into finding symbolism to make it fit. An indication that you have drifted in an incorrect direction is when some parts fit, while others remain disconnected. When you are getting close is when all parts fit within an over all poetrey. When the understanding cross computes on many layers within the theme. God tends to speak on many levels at once.
Another good concept to apply is that prophecy is not doctrinal, and should never be used as such. Wandering there is a real Red flag. The Gospels are for doctrine, not prophecy. False prophets use prophecy for doctrine quite often.
Prophecy is a warning on what is coming down now, in your lifetime, if it is about another timeline it is not prophecy, its history. It was prophecy for someone else. So to really study prophecy you must be willing to freely apply it to your own timeline to see if it truely fits. In most timelines it will partially fit. Only in the correct timeline will the fit fully fit like a key in the lock.
Lucky for us, currently we are in such a time line.
One last observation, most prophecy is given from the perspective of Israel vs the world at large, if you tend to study from an Israel centered perspective it helps.