“Allahu Akbar” is mistakenly translated in the west as “God is great.”
It actually means “Allah is greater (the greatest)” — meaning Allah is greater than your God.
Like everything else with Islam, it’s a statement of superiority and denigration of all other religions.
“...meaning Allah is greater than your God.”
Meaning that Muslims do not worship the God worshipped by Jews and Christians. They worship something different.