Even if this were die-cast (like those Gardena metal connects for garden hoses), which isn't much stronger, it will still break, because you have the showerhead handle hanging on the supply elbow.
Ideal would be a dedicated seperate holder just to grab the showerhead handle, not part of the elbow. Fastened to the stud.
There's a good reason why most of these are plastic, aside from the fact that any machined parts would cost in the hundreds.
The constant brute force on it from daily service puts the strain on the elbow itself, istead of what is inside the wall. Usually there is a threaded elbow coppered from the valve inside the wall, with a short 3-4" horizontal arm "rough", this is what your plastic piece threads onto. You wouldn't want any of the stuff inside your wall to leak.