Language changes when it brings in new words not just randomly doing away with grammar and diction because it’s not convenient.
Actually language changes include randomly doing away with grammar and diction because society doesn’t like it anymore. And you of all people should know that, you read old books, you know how much basic grammar and diction changed between the times of Mary Shelley and James Joyce. There’s two constant forces that work on a language, one is the group of people whose primary use of language is to impress, the other is the group who are just trying to get a point across. The first group makes language larger and slower, the second makes it faster and easier. Which group is on top in any given time frame determines how the language is evolving, it’s either getting more flowery or more contractions. That is the normal evolution of language and you’ve done the reading to already know that.