An infinite, all-powerful, all-knowing creator created a universe where his greatest creation is no better than an avatar in a virtual reality machine.
Maybe the God that created this universe isn't all that infinite, powerful, or knowledgeable? Maybe he was just a good Mormon that lived a good life on the planet Zotho a few thousands years ago and this is the best he could come up with.
You didn’t answer the question. Why would Christians worry if the Triune God of all creation was in control of His creation?
"But by the grace of God I am what I am: and his grace which was bestowed upon me was not in vain; but I laboured more abundantly than they all: yet not I, but the grace of God which was with me." -- 1 Corinthians 15:10
Paul tells us everything he is is by the free, unmerited gift of the Holy Spirit within him. He goes so far as to remind us that even his extra effort of labor is accomplished by "the grace of God which was with me."
This is why the Reformation was fought and what we as Protestants are sadly conceding back to Rome -- we are saved not our own works of righteousness but Christ's righteousness and obedience being graciously imputed to men in order that they believe and be saved, according to the will of God and His plan and purpose for creation from before the foundation of the world.
As I've said to several Arminians who later became Calvinists, just try thinking that every thought, word and deed is ordained by God for His glory. Of course we still err because we are still fallible men and women, and if we say there is no sin in us we are liars, as Paul said.
But by the grace of God, His unmerited gift of the sanctifying Holy Spirit works Christ's righteousness in us and we become what He has ordained us to be -- children of the Triune God.
So if by "avatar" you mean "a graphical image that represents a person, as on the Internet," then we should all be so fortunate as to be "avatars" for, and by and through Jesus Christ "by whom all things consist.)