> For this to be true, we'd had to assume sentience + malevolence.

No we don't. A "dumb," "parrot-like" AI is perfectly capable of large amounts of damage if it just happens to be really good at doing something that, in the limit, isn't very good for humans and is good at replication.

See for example Meta's Diplomacy-playing bots. They were perfectly capable of natural-language deception at the expense of other humans without any notion f sentience or malevolence.

In particular,

> It can only output text.

As we've seen with both private hobbyists and large companies, there is a race to hook up text to computers with real world access. Outputting text isn't much of a limit if that text ends up as instructions to command a real world system.