I am working on a Installation profile and I am trying to figure out 2 things which I didn't find data on them:

1. What is the reason for the make file?
I will try to explain - If my Installation profile can be clone easily using git why would I want a make file?

2. how do I keep my installation profile up to date - Modules, themes, libraries and so on..
In the drush make file I need to mention the exact version of the module / theme so whats the point?
Do I need to update it manually each time?