Taking a design approach start by working out the constraints and then working out what can fit the constraints.
So for your project I’d suggest constraints are something like:
* built with react * basic functionality can be built over a weekend * no redux/database backend * fun and interesting to devs * add your own..
Then just see what you can think of that fits.
React let’s you do live updates across the page based on what happens, lean into this.. what’s a fun way you can push this constraint. What if your thing had just one button?
That’s where I’d start.
There’s many projects where someone says I set these tight constraints for fun and look what I made. Memorable to me especially was 1D Doom which was just a 1 pixel line but had all the sounds and each element in game had its own pixel colour.
Tight constraints make for better creative projects.
Further if you really can’t think of something fun/creative, connect with a cause you care for and help make a tool that helps them.
Generally...
(1) look at problems I have or things that annoy me, the easy part
(2) find a better way to do that thing, the hard part
(3) build that better way, the tedious part
For your case, pick something tried and true. You don't have to do something new, but don't pick something overly complex to reach viability either. Picking something that can become complex is good however. Pair it with something else you are passionate about is likely best.