It is possible to use a Custom Module and Dynamic Content to create blog-like content in sites.

In doing so, some things are lost, like "Categories" and some things are gained, such as being able to use a filtered View to select which items to display, and workflows to be able to stage blog posts for display in the future.

A major downside, though, is that to use html, you don't get a WSYWIG editor.  The multi-line text field of CRM modules can contain html which renders correctly by Dynamic Content.

Whether or not the trade-offs are worth it, is up to you.