This seems misleading. Rollup doesn't ship with an uglifier/minifier, and Webpack ships with UglifyJS. So what you're really comparing is UglifyJS vsthe Closure Compiler, however both webpack _and_ rollup have plugins for utilizing the closure compiler:

https://github.com/roman01la/webpack-closure-compiler

https://github.com/camelaissani/rollup-plugin-closure-compil...