Language is a barrier, and barriers have had a huge part in developing and maintaining cultures (Think mountains/laws/etc). Language keeps many cultural thought

Language is a barrier, and barriers have had a huge part in developing and maintaining cultures (Think mountains/laws/etc). Language keeps many cultural thoughts, perceptions, artifacts, and philosophies from both entering and leaving. Like you said, the idea of everyone speaking the same language could never result in total homogeneity. However, you could lose out on some of the deeper insights and developments without language to filter out the noise. I believe that it would be a huge step backwards, but obviously you may disagree.