> In fact, today it's almost a recommended practice for large web applications and it's called "tree shaking". ECMAScript modules are inlined into the same scope. It makes the JIT work easier because it now works with symbols instead of `require(foo).bar` calls to speculate on. It makes most web apps run better, both in bandwidth and compute.

That's bundling, not tree shaking. Tree shaking is an optional additional process during bundling where unreachable code is automatically removed.