Not necessarily. At the moment, we don't really understand it at all, so the only thing we know about it is that it can be produced under the conditions at the centre of a gas giant. Part of the idea of studying things like this, aside from simply wanting to understand how things work, is to find out if there are other ways to make and/or use it that don't require such extreme conditions. You can look at something like superconductivity for a similar idea - it was originally discovered under very extreme conditions that were basically impossible to actually use in any sensible way, but from understanding things better we now make routinue use of superconductors in a variety of places. It took over 40 years to go from discovery to a practical application. Nuclear fusion would be another good example, although that one's been a bit less easy to get to practical use.
So maybe metallic hydrogen will never be easily produced on Earth, and maybe it doesn't have any actual use even if we can. But on the other hand, maybe it will. We know we cannot realistically produce it on Earth right now, but without learning more about it, we really just don't know what might actually be possible.