Some teams may use it at the big companies and I myself have used lesser performant languages at some of the big companies but only for smaller stuff. For the widely used stuff which big companies do a lot of, you need high efficiency and javascript ain't gonna do that.
One of my co workers worked on a 5 person project for half a year that just refactored a core algorithm for a heavily used product and that halved the 5 million dollars a year in hardware costs and that's not expensive public cloud cost but the highly efficient internal data center costs and all of the code was in C++. Writing any of that code in javascript would just be wasting money.