That's actually not true. The Closure compiler has certain restrictions on the Js it accepts for advanced mode compilation, so you can't throw just anything at

That's actually not true. The Closure compiler has certain restrictions on the Js it accepts for advanced mode compilation, so you can't throw just anything at it. The advantage is best-in-class dead code elimination, which is also why Closure was chosen; to distill the CLojurescript standard library into just the parts needed for a web page requires good DCE. Recently, other Js projects like Rollup and Webpack have gotten good DCE, but when Clojurescript was started, there were no other serious contenders.