The person who coined the term "prompt injection" has the same gripe, because the original term genuinely did mean an attack using untrusted user input, a la SQL injection. But it's been conflated with jailbreak attacks in general, muddying the term.
Example of a bona fide prompt injection: white text in the background of a resume PDF, attacking a job application portal that uses LLMs to filter applicants. No privilege escalation is involved to give the candidate top marks on their resume screening.
Whereas a non-prompt injection jailbreak would be bypassing a safety filter, such as how Morse code might get past the filter and allow a user to request other people's cryptocurrency be transfered away. This is more akin to finding a poorly-secured, public facing API and then exploiting it.