First, Vue has only a few simple rules and paradigms to learn. The templating language feels and works natural but is still very powerful. It is as close to pure javascript as templating can get. All the other logic that supports the rendering (state, computed properties, event handlers (methods) and component properties) are easy to understand and integrate. However, what makes vuejs so special is also that you are still in full control, while serving a very good standard. You don't have to set up code splitting, routing, transpilation, service worker etc. With Vue-Cli you can choose from many presets that suit your requirements, or easily integrate your own plugin.
I recently organized a lightning talk about how vue helps in making the right decisions: slides.com/martinmuzatko-1/composing-modern-uis