It wasn't a hack though. Characters were low level addressable data. It's no coincidence that on machines that had a 6-bit wide character set the smallest addressable data (a byte) was also 6-bits (I know ASCII is 7-bits but that was to reduce transmission overhead or allow for a parity bit when required, eg on punch tape or cards that often supported 8 columns of bits).

The way machines worked back then would be you'd address a byte of data, that byte contained instructions. Those instructions were sometimes printable data, it was sometimes formatting data, and it was sometimes control data.

It wasn't until operating systems became more sophisticated, hardware become more sophisticated and the two became decoupled, that character encodings became the abstraction for rendering text that we think of them as today.