I suspect that the placebo effect can be very strong in anxiety situations.
And on top of pure placebo. The whole rite of going to the kitchen and prepare your little pill has a calming effect in itself.
And maybe matcha is the same. Its preparation is slow and requires attention.
Much like smoking, it’s difficult to know how much of the calm it provides come nicotin or from slower/deeper breathing, just going outside and talking to strangers.
I have chronic insomnia that is turning severe, so I really want to believe these things work, but so far, they’re all very pricey and completely useless on sleep.