Everything is representable as binary, but not everything is binary. The abstract concept of 'A' has no inherent binary representation, and 0x41 is just one of the options. Representing Pi or e calls for even more abstract encoding, even though they are a very specific concept. Text is not binary, but text has to be encoded to binary (one way or another) in order to do any kind of computer assisted processing of it. But we tend to think of text in abstract terms, instead of "utf-8 encoded bytes", hence this abstraction is useful.
What if the computer isn't binary, but it needs to talk to a binary computer? Then you definitely can't go "oh, this text is binary anyway, I can just push it on the wire as-is and let the other end figure it out".
