A finite god that anticipates endless improvement is terribly static, immobilized, and boring.
Nearly all of his being is in a potential state, not yet actualized. Since this finite god’s improvement is never-ending, most of his potential will never be realized. Almost the entirety of this god is static or “slow”, not yet put to full use, and not yet up to speed.
As though watching a demigod toddler learning to walk, his worshippers clap and say, “But at least he’s getting better! He’s not completely still. And we can relate to his limitations.”
But the infinite God is completely actualized. None of himself is potentially better. His whole infinite being is active, both in the inner life of the Trinity, and in the love of his creation.
He isn’t bumping up his own limitations, having to stretch himself. He doesn’t need more gas in his fuel tank. He isn’t upgrading along the way.
Since he is entirely infinite, and all of his attributes coextensive, and completely perfect, the fullness of his perfection is active.