I quickly wanted to give a try bundling React with esbuild and from the first few tries it is really fast. However I did not build a very large production scale application. Therefore I can't verify all the claims.
To install refer the installation guide
To create a bundle with React all files should be in .jsx extension and to bundle use the following command,
$ esbuild index.jsx --bundle --outfile=out.js
out.js which is the bundled. Note that there are many options, which you can refer using
--help in command line.