> This is an assumption you are making that many (most?) religions do not.
We're really only talking about the Abrahamic faiths here, which are the ones making claims about God being omniscient, omnipresent and omnipotent.
Any limitation to God's abilities implies that God is not all-powerful. If it is the case that this universe of sin and decay and the literal hail Mary of self-sacrifice on the cross with the result, as described in the book of Revelations, that the vast majority of humans who have ever lived will still burn in Hell for eternity is really the best God can do, then God cannot be all powerful. If God is all powerful then everything is arbitrary to Him. He chooses to allow evil. He chooses not to forgive sin. He chooses a pyrrhic victory at the end of time where evil still mostly wins.
Incompetent, yes. Malicious, certainly. To quote George Carlin, this is not work that belongs on the resume of a Supreme Being. All powerful? Obviously not.
Other religions don't have this problem. The gods of many other religions are limited in their capabilities and often exist within the framework of a cycle that allows constant redemption and renewal through reincarnation. In many ways, the cosmos itself is the highest power, and the gods are just what sits above humanity, but it's all still a part of the same flawed yet transcendental machine. There's always hope. With the Abrahamic faiths, there is only always existential dread. God by default will cast you into perdition, your sins are absolute and immutable, and if you fuck up the one life you have there are no second chances.