It seems to me that a past advanced civilization would have left behind durable objects made of metal alloys, stamped or machined metal parts, fasteners, hinges, large machines, bits of high quality glass and possibly even plastic or composite items. I don't recall that we have ever seen examples of any of these things. It is fun to imagine such scenarios but there is just nothing tangible.
You're making the assumption Atlantean technology was like more modern Western Civilization technology based on petroleum, steam, and the internal combustion engine. Perhaps that was not the case with Atlantis. I'm just speculating here, but isn't our tech based on the occassional accidental discovery that the Atlanteans never made? Perhaps they discovered something that we haven't, thier own accidental discoveries? There are other avenues of tech we just haven't followed out of convenience and tech suppression by those who gain from our consumption.
