Some very powerful people can probably do that, but it’s tricky. You are making a permanent material object out of nothing.
Biological/organic matter is much easier to do that with than hard minerals etc. I mean, yes, you can channel a chunk of titanium from the elemental plane of earth, but actually fully shaping it into a weapon, particularly a sharp weapon? Difficult, and generally you want some sort of alloy for the metal Some things are just easier to do the manual way, the energy expenditure is huge.