Would suggest adjusting the items further down the list in decending order by GH stars ... at least it's a consistent order that way.
Usually don't like these kinds of lists, this one is a bit more complete than most and not too opinionated.
On "Material-UI" ... Material UI is a component library and implementation supporting the Material Design approach to applications.
On "react Bootstrap" .. React Bootstrap is a component library compliment to the Bootstrap CSS library. It uses the stylesheet output, but with its' own components.
Would lean more towards fact, less on opinion.
probably better to use a combination of setInterval and/or requestAnimationFrame and update when the seconds actually changes.. with the setTimeout loop, it will get a jarring 2s shift on occassion... more noticeable with a digital readout, but it will happen as you hit borderline timing on the second.
While this is a cool abstraction, I do think that React is here to stay for a very long time, and that JSX based component library options are also likely to stay around for a very long time.
While the DOM is relatively stable now, this wasn't always the case, and with the expansion of WASM libraries and tooling that will come in the next few years, it could get interesting. An abstraction like in TFA might be better served with a WASM targeted application management layer/framework.
It's a bit opinionated. No test setup anywhere in sight. Redux Saga chosen over say thunks. As mentioned no Saga examples. Organized by type, not feature.
Really doesn't add much over create-react-app imo.
Both of these components don't seem to have anything actually wired for click events, feels like half the example is missing and not in a way that makes things really understandable.