The Bible states outright that...

They state outright in the Bible that Satan is not omniscient, Satan is not the omniscient protagonist to gods onniscience. This occurs in many passages as Satan is the accuser, the tester of faith and fidelity …

Problem is, if Satan were omniscient, Satan would never bother to test in the first place because the outcome of all those tests would be known…

But, does this all hint to a deeper aspect of reality?

That neither god nor Satan know our future…

Why would God need anyone tested if god already knew the outcome (and tests in the Bible are super fucking brutal too!!)

I rest my case there.

Remember the Bible was written by men not by God but in answer to the question
Satan was allowed dominion over Earth because he wanted the power to test man