And dealing with strings isn't fun in many other languages or runtimes or OSes.

e.g.1. C# "Strings in .NET are stored using UTF-16 encoding. UTF-8 is the standard for Web protocols and other important libraries. Beginning in C# 11, you can add the u8 suffix to a string literal to specify UTF-8 encoding. UTF-8 literals are stored as ReadOnlySpan<byte> objects" - https://learn.microsoft.com/en-us/dotnet/csharp/language-ref...

e.g.2. Erlang/BEAM/Elixir: "The Erlang string type is implemented as a single-linked-list of unicode code points. That is, if we write “Hello” in the language, this is represented as [$H, $e, $l, $l, $o]". The overhead of this representation is massive. Each Cons-cell use 8 bytes for the code point and 8 bytes for the pointer to the next value. This means that the 5-byte ASCII-representation of “Hello” is 5*16 = 80 bytes in the Erlang representation." - https://medium.com/@jlouis666/erlang-string-handling-7588daa...

This refers just to Erlang's string() type, not BEAM strings in general; it's just a bad default. If you're not using binaries, you're doing it wrong, and that's exactly why Elixir's strings are UTF-8 binaries.