Excel macros are deterministic, don't leak BI and PII, aren't malware, and don't cost an extra engineer's salary per engineer. Comparing them to Claude is quite a disservice.
It's funny you mentioned excel macros not being malware. Various scripting systems provided by excel has been a long standing malware vector.
Not to forget versioned inside the document. The same spreadsheet produces same answers if it is not edited. Same can't be said from programs that can be recreated over and over again.