I agree, LLMs definitely sand off a lot of personality, and you can see it in writing the most, at this point I'm sure tons of people are subconsciously trained to lower the trust for something where they recognize typical patterns.

With the code, especially interfaces, the results will be similar -- more standardized palettes, predictable things.

To be fair, the converging factor is going on pretty much forever, e.g. radio/TV led to the lots of local accents disappearing, our world is heavily globalized.