It’s not that it was written poorly, so much as it was written in and for a Bronze Age culture that no longer exists.

The modern audience isn’t reading it with the cultural context in which was written, and without that context it’s as you say, awful.

A lot of the imagery is just allegory- especially in the prophetic bits. The vast majority of human history was written in a time where saying “[that asshole ruler] is an asshole” wouldn’t get you killed, or saying “[that jackass of a priest] is batshit crazy!” Would get you tortured and then killed.

So they use allegory and symbolism to say it, and any one who was meant to be the audience would understand that. The book of revelation, for example, was in part about Nero (the antichrist,) (it should be noted revelation was probably written by John of Patmos, on the island of Patmos. Which is famous for always having… how shall we say it… “interesting” mushrooms?)