You're taking a widely agreed on premise (mystical experiences happen in religious stories) and leaping to a conclusion that said premise does not inherently support and that the highest authorities on those religions would disagree with (drugs caused those experiences). There's a pretty enormous gap between those two thoughts. That gap needs actual evidence to fill it up.
The concept is interesting and definitely has some logic behind it. It's possible it's true. But right now, there is exactly ZERO evidence to support it. So presenting it as fact is completely incorrect. With the facts we have right now, it is equally possible that these experiences were the result of sleep deprivation, hunger or thirst, the human brain somehow working differently thousands of years ago, mental illness, outright lies, metaphor, simple story telling, etc.