It seems relevant that a lot of these things were fairly notorious clichés even before LLMs, which just intensified the phenomenon. They were what people tended to do who wanted to sound smart and sophisticated but didn't have a developed voice or anything in particular to say. Indeed, I'm fairly sure this is why LLMs sound like this.
Indeed,
This is true, although I can still get behind "use fewer cliches" regardless :)
AI is so original that it can’t make cliches out of decently-worn phrases and constructions by itself.
A lot of these things were well-known clichés already before LLMs, used by people who wanted to sound sophisticated but weren't articulate or didn't have anything to say. That's why LLMs sound like that.