I could literally type for days about the benefits of docker over a $10 digital ocean server, but no one would read it.
What I will say is this. If you're writing a trivial application that you and only you will ever need to work with, in an environment completely controlled by you, and you have a recipe that works - you're right, Docker probably isn't for you.
If you, like me, work with a huge product suite with many buildtime and runtime dependencies (services and applications), with many different runtime configurations, where even automated installation can take up to 15-20 minutes because of the sheer amount of work that's going on, there's a massive massive amount of efficiency to be gained in the dev/test/release/packaging process, let alone the massive amount of efficiency to be gained by the ops team in working in foreign environments.
There are certainly lots of other use cases (PaaS/SaaS are easy,) and those are valuable business building tools, but less interesting to me personally.
What I will say is this. If you're writing a trivial application that you and only you will ever need to work with, in an environment completely controlled by you, and you have a recipe that works - you're right, Docker probably isn't for you.
If you, like me, work with a huge product suite with many buildtime and runtime dependencies (services and applications), with many different runtime configurations, where even automated installation can take up to 15-20 minutes because of the sheer amount of work that's going on, there's a massive massive amount of efficiency to be gained in the dev/test/release/packaging process, let alone the massive amount of efficiency to be gained by the ops team in working in foreign environments.
There are certainly lots of other use cases (PaaS/SaaS are easy,) and those are valuable business building tools, but less interesting to me personally.