That really depends on what we're looking for when we're asking "Was there ever an Atlantis?"
If we're talking about an island civilization that existed beyond the Straits of Gibraltar, somehow had contact with the cradle of Western civilization, and otherwise fit exactly as Plato (or More, or whoever) described it as? Almost certainly not. That much is another Greek morality fable- one of several- that was spun to have some nationalistic and cultural sting and root for the home team. As esaciar says, the dramatic themes and tools Plato utilized were not alien even in his own time, and could easily be seen as fictional. It's not impossible Plato meant it as a sort of send up to Athens itself and what it had turned out to be (since he was not a fan of Democracy or Res Publica).
If we're talking about something that was loosely based on this? That may be worth talking about more. The savage, advanced but barbaric maritime empire squeezing Athens and a lot of the rest of Greece is a possible jumble up of the old Minoan Empire that we are pretty sure existed on Crete, was (relatively) advanced, and did indeed have a bad rep with the mainland Greeks that gave us things like the myth of the Minotaur. The idea of cataclysmic destruction of an entire island civilization could come from even more places, both half-jumbled ancestral remembrances of the Minoan collapse and other things like a few explosions that occasionally blew entire islands and city-states of the Aegean off the map. While the story Plato crafted is fictional, it's quite likely a lot of the ingredients he used to cook it up were at least partially not.
It's almost certainly not historical like we know the Trojan Myths are not. But it's possibly crypto-historical or historical fiction, for the same reason we are pretty sure Troy existed (as a Hittite vassal/outpost), there was a pan-Greek war against it, and war happened.