No new OS today will ever be used by any significant number of people without 1) a working web browser and 2) hardware support for laptops, phones, wifi cards... you know... stuff people already have.
SerenityOS might get a working browser. Not very likely, but it might get it. The #2 condition will only be solved if it somehow "imports" Linux drivers or wrap Windows binary drivers in a compatibility layer (like Linux used to have for wifi).
Their policy to not use any external code or libraries is what will finally kill the project. It's simply not possible for them to rewrite any significant portion of drivers needed. Not even Linux can keep up and they have lots of contributors from the hardware industry.
They could probably make SerenityOS a VM-only OS. That could work. Run Linux as a HAL and SerenityOS as a UI on top. But then, why not write a complete Linux userspace to replace Gnu?
SerenityOS serves as a cool side project for those who like to tinker with OS dev. I don't think it was "born" with any other goals in mind. Neither was their browser project, it just happened to turn into something a lot more serious.
