In the modern day, people dismiss many aspects of religion by accusing them of being hallucinogenic visions or just normal dreams.
My question is whether or not similar things happened among ancient religions, towards one another, or did the lay person of the time accuse religions of just being dreams or visions rather than fact? My question is focused on Ancient Israel, but if you have other answers from other ancient religions, I'm curious to hear these aswell.
Not Israelite but most definitely, if you read the Qur'an it defends the Prophet against the accusations from some of the Meccans that he was a madman or possessed (majnoon).
In surah qalam:
Nun. By the pen and what they inscribe,
You are not, [O Muhammad], by the favor of your Lord, a madman.
And indeed, for you is a reward uninterrupted.
And indeed, you are of a great moral character
So you will see and they will see
Which of you is the afflicted [by a devil].
Of course jews and Christians continued these accusations. If you read Dostoyevsky, you'll know that even much later it was a common European myth that Muhammad pbuh was epileptic.