Provide a way to use styles on both blocks and sections

Can you provide a real world use case so I can better understand why?

The current workaround is just to create the style twice. I assume that's annoying enough for your use case, so I'm curious what it is

A background color class might want to be applied to a specific block or an entire section.

As a followup on real world use cases, I am currently working on a Drupal project, where a color palette has been defined. We need to be able to both create a dashed border, and/or a background color for various content, and styling only fx. blocks is not sufficient.
This can be exemplified by the following: We have a bunch of custom blocks, which we want to wrap in a dashed border. If we add the dashed border to individual blocks, each of the blocks will be wrapped, which is not the intention, so we need to be able to give the section containing the blocks the dashed border styling.

I have a similar use case on a decoupled website. We are also using background colors but in this case I need to send the same color variable to the FE to change Layouts and Blocks. For now I am using a Select list for the blocks because I can not apply the color background to specific blocks. On this way, I have background color on blocks for specific use cases and layout builder styles for the layouts.