I am considering getting a full face mask. I can think of two reasons I want it. One of them is visibility, so I can have a wider arc of view. The other is for safety. Seeing as how almost all problems underwater resulting in death. Are from a person going unconscious and losing their regulator? It seems that this would solve that individual problem. But for the life of me I can't figure out why they're not more common? I know they're expensive, but is that the only reason?
In fairness, I think there are MANY good 'half masks' out there. That is what I have been diving with for several decades. My personal preferences are just that, but - as a point of reference - I generally favor a low profile mask, such as the Mako, the Sherwood Onyx, the Aqua Lung Technica. For that matter, one of my long time favorite masks is also the least expensive mask we sell in the store - a Sea Dive Caribbean. Great mask - simle, functional, etc. A common theme across these masks - all of these FIT ME. I don't have a problem seeing people around me. I just turn my head.
Now, I also regularly dive FFMs, I love them ('them' being - for me - an OTS Guardian and an Ocean Reef Predator), and I actibvely encourage divers to try them. A FFM takes the cold off my face in chilly water, it is easy to breathe (because I use my mouth and nose), the visibility is great - it doesn't ever fog up underwater, etc. Learning to deal with the incredibly unlikely scenario of needing to 'bail out' from a FFM is quite easy. If you run out of air (aside from, 'BAD on YOU'), you simply pull the mask off and breathe from someone else's alternate. No big deal.
For the general recreational diver, I cannot say the FF mask is conspicuously 'safer'. When diving a FFM I don't worry about my mask being knocked off by an errant fin of another diver. That just doesn't happen with a FFM, unlike a half mask. Maybe, that makes it a bit 'safer'. Personally, I view that feature as simply a matter of greater functionality. A properly fitting FFM just doesn't leak. That is not always true with a half mask. In those unusual cases where a diver may have a medical condition that might render them unconscious underwater (e.g. a cardiac rhythm disturbance) a FFM is actually MUCH safer. But, those situations are uncommon.
I have been working recently with a recreational diver who decided he wanted to try a FFM. We got in our pool, he tried a FF mask, he loved it. He did the FFM course, he bought a mask. He has said several times since then that he wished someone / anyone had told him about FFMs as an OW student.
Half masks are great. But, based on your comments, you should probably at least try a FFM, and see if YOU find it offers YOU something that a half mask does not. It is not simply a matter of 'skills' with a half mask, although those are certainly important. It is a matter of what YOU find to be best for YOU as a diver.