This article praises everything Zig does and lists no negatives of its design. I'd recommend a different article for a balanced take, particularly regarding comparisons with Rust: https://www.scattered-thoughts.net/writing/assorted-thoughts...
No standard utf8 string library is scary - I would happily learn all the mem gymnastics to make this work but fiddling with competing UTF8 libraries as is the case with C/C++ is just not my cuppa.
There are functions for handling utf8 in the standard library.
Well, there's functions for working with code points within the bytes that (may) make up utf8 strings.. in order to do actual string level manipulation a library is needed (such as https://github.com/jecolon/ziglyph or others)