Indeed, representing text as a sequence of Unicode code points is fundamentally wrong.
There are no operations on sequences of Unicode code points that are more correct than an analogous operation on bytes.
(Everyone's favourite example, length, actually becomes less correct—a byte array's length at least corresponds to the amount of space one might have to allocate for it in a particular encoding. A length in codepoints is absolutely meaningless both technically and linguistically. And this is, for what little it's worth, close to the only operation you can do on a string without imposing additional restrictions about its context.)
There are no operations on sequences of Unicode code points that are more correct than an analogous operation on bytes.
(Everyone's favourite example, length, actually becomes less correct—a byte array's length at least corresponds to the amount of space one might have to allocate for it in a particular encoding. A length in codepoints is absolutely meaningless both technically and linguistically. And this is, for what little it's worth, close to the only operation you can do on a string without imposing additional restrictions about its context.)