> Why would their algorithm stop to work if your code gets large? It's not some kind of magic. :)

Their algorithm always fails on certain cases. If your code base is larger, it's more likely to contain those cases.

Example case that will always fail:

    const x = { foo: () => {} }
    x["f" + "oo"]();

Now rename foo to bar.

Yes, this is a contrived case, but we had similar code in production at my last job.