This is incorrect

Are you certain? Not OP, but a huge chunk of early RFCs was about how to let giant IBM systems talk to everyone else, specifying everything from character sets (nearly universally “7-bit ASCII”) to end of line/message characters. Otherwise, IBM would’ve tried to make EBCDIC the default for everything.

For instance, consider FTP’s text mode, which was primarily a way to accidentally corrupt your download when you forgot to type “bin” first, but was also handy for getting human readable files from one incompatible system to another.