Commonly used it not a business reason.
Every app/feature you install should have a clear purpose and be able to prove it’s worth.
Kitchen sink apps are generally mediocre for each sub-feature and just make it easy to make bad kitchen sink websites. The only reason to use them is to burn the time&money on purpose to learn the concepts and the mistakes.
Alot of themes have a size chart feature, or setting that can be used to add a size chart, for pdfs use a metafield defintion as a dynamic source in something like a rich-text block.
For vintage themes there is a customization
For OS2.0 themes the above customization could be implement using a custom-liquid section or block.