Another +1 for web components. We have been using this paradigm exclusively for new features and it's really fantastic. Template literals eliminate the need for things like JSX and you can just use small simple libraries for state management and data binding. Keep every web component in it's own NPM module with it's own test suite and dependency resolution, and have a single package.json that describes your entire app.
Would you recommend any specific combination of libraries boilerplate/starter kit? (I suppose I should just search npm, GitHub..) I feel like there are almost too many libraries for, i.e., transforming template literals to HTML, data binding, state management, etc. I know "do one thing only", but it can be daunting to figure out an optimal integrated setup.
Is there a popular/well-used set of tools for the kind of web-component based projects that you're describing? Polymer is one, I recall - wasn't too keen on it last time I looked at it, would prefer more minimal/modular..