Applying Greek thought to "Ehyeh asher ehyeh" is an attempt to get at something that "explain(s) itself", I am sure you are familiar with St. Thomas Aquinas and his five ways.

Yup. Being a theist, I suspect God is in some way the cause of everything, although I'm not really smart enough to understand how that could be. I leave the answer to some future genius (or, more likely, superintelligent AI.)

Saying we have a logical reason for things existing seems to be on that same level of reasoning and appears to just add another turtle to me.

Really? But logic, as a mathematical construct, "exists" (in the sense that it exists at all) independently of physical objects; a calculator on mars will get the same result as one on Earth, even if they have no causal connection. Logic seems like it can explain things in terms of platonic mathematical structure, not contingent physical causes.