It can but don’t stretch it too far. Instead of a pure
Business need > Requirements > Specification > Build
consider from the business need what can be done out of the box, then prioritise from there for the remainder.

There are a wide range of extension products that have good user bases. This can save you lots of time and convert what would otherwise be expensive software development job into a configuration job a BA can do. Check out CorasWorks and Syntergy in particular.

Consider if you are a vendor and your primary sales income is from software development and requirements studies. You get the “hammer-nail effect”, where every problem you have (the nail) looks like it needs a hammer (their software developers). We have come across too many train wrecks where unnecessary software development has added cost and in fact impacted on standard SharePoint functionality and response times.

Yes this can be helpful as a last resort (before altering the requirements; information design configuration; proven third party products). There are amazing things you can do in bringing together information from multiple systems - consider use of the CorasWorks Data Integration tool