A baseline should be classed as a starting point and not a complete solution. The idea to too create a baseline that offers both security and functionality. Once you have this, you can start to build and shift the balance depending on the business need.
The following is taken from the security baseline learning module which I strongly suggest you read (They are awesome!).
Below follow those learning modules and I’ve basically built on top of it and expanding on the reasons why you would implement these solutions/policies.