Hm, depends on the business, I guess. Because from my experience, most business algorithms are proprietary and don’t have proper specifications. You can’t just use them somewhere else. You have to recreate them from scratch.
Only roughly half the world believes in SP's. The other half (like me) believes that writing even the barest of hints of logic into SP's is a serious crime.
So you'd rather write the same logic in every app, and trust that every developer of every app does the same and gets it identical? Good for keeping busy I suppose but if I were your manager I wouldn't pay you for it.
Business logic and algorithms is what it’s all about.