Speaking more abstractly since I haven't looked at the CVEs in question, but an attacker directly accessing coreutils on your system isn't the only possible attack vector. Another potentially interesting one would be them expecting you to run coreutils on something under they control. For example, a hypothetical exploit in grep might be exploitable by getting you to grep through a repo with a malicious file.

A more concrete example would be some of the various zero-click iMessage exploits, where the vulnerable software isn't exploited via the attackers directly accessing the victim's device but is exploited by sending a malicious file.