I started the project with create-react-app a long time ago. I've since updated it to latest versions of webpack and switched from React to Preact. It's not using any hooks or any modern React conventions, but I don't really need it. I've kept it simple, the only two libraries I include are preact-easy-state and preact-router. Everything else is components I wrote. All images used are SVG, I'm using LESS to compile to CSS, and everything is bundled into a single HTML file that gets gzipped down to about 48KB. I've tweaked the default Webpack configs to get exactly the payload I want. This gets compiled into my ESP32 firmware and served directly from flash. The web app handles all devices configs as well as wifi access point config, and it controls all kinds of device functions using custom sliders and buttons, etc.