“No options” simply isn’t true. Here’s a guide to many of the options: https://hasufell.github.io/posts/2024-05-07-ultimate-string-...

Now if you’re asking why the basic prelude String type remains as it is, that’s because changing it would break more code than it’s worth, at least as far as prelude’s maintainers are concerned. This is no different from how standard C strings remain a null-terminated sequence of bytes even though that’s been awful for everyday use for at least 30 years.

To clarify, It looks like Haskell got better string types around 20 years ago.