Why does the function work faster in the main and synchronous thread than in a separate and asynchronous one?

[Vitaiii]

I run the factorial function first in app.js synchronously on a shared thread. And then in app.worker.js on a separate asynchronous thread. In a separate asynchronous thread, the function should run faster. However, I have everything conversely.codesandbox

[EladBahar]

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