Doesn't it seem logical that...?

... when we're talking about these ancient (apparently) advanced civilizations we should lower our estimation of them in the fact that they died off with little or even no tangible evidence of their genius. If Atlantis was an island certainly they were a sea going people, if they reached a great level of society they would have needed resources from another place. Therefor why don't we have thorough, specific recorded evidence of their civilization and their technologies from present peoples in neighboring areas. Oh right, no one even knows where they were. If Japan sunk tomorrow, in five thousand years people would know who they were and what they did in detail. An advanced people leave that kind of footprint.