I don't think your "it is source as you can convert it back into source" argument holds water as all the Erlang formats can be decompiled into Erlang source code, including the final bytecode itself.
I think you're overthinking the cost of compiling to source, and also underestimating how common it is.
I think you're overthinking the cost of compiling to source, and also underestimating how common it is.