Benefits of docker

I use docker only for wordpress (basically for developing themes).

When developing for Plone, the 'new way' of using pip makes it very easy… just add a policy product and the only thing I copy is the var folder.

Without knowing too much about docker: what are the benefits of developing with docker?

For newcomers: Someone else figures out the build time requirements, like libjpeg for Pillow, for you. Enables you to concentrate on the main problem at hand and not the systems requirements side of Plone.

Using Plone and Docker for development makes no sense for me. You often have buildout failures. Restarting a buildout inside Docker restarts the complete build process from scratch. A buildout on a normal system resumes. Analyzing buildout errors within a container is a pita. Docker is an efficiency killer.

I'd assume one replaces buildout with docker. Both solve about the same scope of 'this needs to be there and there on the filesystem for x to work'.

Docker for the sake of development only makes sense for components that need to interact with Plone like database, external services etc. Docker for Plone development said makes no sense to me because it does not solve any problem..or where and how would Docker help me with Plone development instead of using Buildout?

There are solutions for this.
For example you have a Dockerfile that doesn't fail on buildout failure and builds on its own image.

The only way I could get a newcomer who wasn't familar with python and buildout and decoding build errors was with docker. Esp on windows.
For example I had someone writing robot tests for me using a few docker commands. esp easy with docker images like selenium/standalone-chrome