Pros & Cons of using compare & Deploy with On premise

Can someone list out the pros & cons of Compare & Deploy functionality Appian provides.

And What could be the reason one should go with separate outside Automate process of Deployment for e.g

Export Package and Update into Repo and move along in upper environment via DevOPS tools and if there is any Database change then also use Repo to upload and then Move along with Jenkin Build and other tools.