HubSpot themes make life easier for developers, as well as marketers. For example, developers can create reusable modules for their themes, which means less coding. With the introduction of themes into the developer’s toolkit, HubSpot has further strengthened its philosophy of component-based software engineering, which essentially means you develop once and use the coding everywhere.
Additionally, developers can also sell or offer their themes for free on the marketplace. It could be another source of income.