React.js is suitable for constructing single-page applications (SPAs), engaging user interfaces, e-commerce platforms, and data dashboards because of its effective rendering and component-driven architecture.

Angular is the best choice for enterprise-level applications on a large scale, including web applications for enterprises and e-commerce platforms.

Unlikely! Both frameworks are constantly evolving and remain major players in web development. The choice will depend on project requirements.

React.js is a JavaScript library used to create user interfaces by utilising a component-focused method. Angular is a robust framework with functionalities such as two-way data binding and dependency injection, designed for extensive applications.

React.js tends to have a lower initial development cost due to its lightweight nature and flexibility. Angular may require more upfront investment due to its comprehensive built-in features.