How can I always have the node title display on top of a background image? With Drupal 8, the page title is available through a block now. We have several content types where we have an Image field (field_image) and we constantly have to write templates per content type to place the title on top of the image.

It would be nice if we could use the view modes of each content type or some module to do this. Basically, something that does "take the field image, set it as a background, and place the title on top."  

Is there a better way to do this programmatically as we cannot find any other way to do this?
There is several ways to solve this 

1 make your own module

to do what you described 

2 add theme templates

for each content type as you described

3 Use background_image module

The module is available for Drupal 8 promises to do just this (I meant to use it but have not actually)

According to the the project description provides a way to insert token values


  Token - Provides a way to view which tokens are available to use when
  adding overlay text for a background image.


So you can probably use it with a field token to accomplish what you need