The use of kilo for 1024 in computers precedes the formalization of kilo as an SI prefix. SI should have used a different prefix instead /s

Kilo (chili-/chilo-/*kʰehliyoi) is an Ancient Greek/Proto-Hellenic word literally translated as "one thousand". The word can be traced back to Proto-Indo-European, which means it's as old as any language we're aware of, though Proto-Hellenic is when the meaning was fixed to 1000.