Romanization is the process of introducing conquered people to roman culture. how did romanization contribute to the strength and growth of the roman empire?

Early Roman Empire economy was based on conquering and that's how it's economy grew more conquering more growth in economy. Being under roman rule wasn't to harsh as they say "when in Rome, do as Romans do" which meant if when Romanized you had to be apart of the culture and people followed that. Great Rome didn't become great because of its army or its  government Rome became great because of its people.