re: “I think it serves as vacuous because it really doesn’t address the condition of the seeker nor does it really define Jesus in even the barest of terms.”
So tell me, then, in Acts 16:29-31, was Paul’s answer to the Philippian Jailer’s question, “What must I do to be saved?”, vacuous too? All Paul told him was, “Believe in the Lord Jesus, and you will be saved.” That’s even shorter than the “sinner’s prayer”. Just how much theology must one understand to be saved?
But who is the Lord Jesus Christ? How can you believe in someone you do not know?
I agree... it’s only “vacuous” in a vacuum. Circumstances are being given short shrift. It’s easy to blame the plow when it won’t turn concrete into a garden.