I went to quite a few Phish and Dead shows in the 90s. Trust me. They were plenty psychedelic.
I lived through the psychedelic era and I've been to plenty of Dead concerts and a few Phish concerts as well. We didn't consider The Dead in the same category back then. And I still don't consider them now. Ditto for Phish which appropriated elements of the Dead sound and style and did it pretty well. Fine enough band even if they did strike me as being a little too self-conscious and trying just a little too hard at times. But they're still worth listening to and better than a lot of what was out when they were around.
But this is all just me. Others may see it differently, and I'm good with that.