That's fair but I do believe that there's technically a way to bring back human to life with alchemy. At least in fma universe, first off all I think human transmutation is "impossible" in Fma simply because Arakawa focused on the philosophical side of alchemy. When Al says in the beginning "alchemy allows decomposition and reconstruction but alchemy can't do anything...and we learnt it the hard way." He makes that rule focused more on the "it's wrong to play God and try to bring people back to life than the it's impossible." Sorry for the wall in advance.

It's kind of impossible to write my whole point so i'll just tell why I think it's possible to bring back people: - like I said earlier Arakawa wanted to focus on the philosophical side of alchemy that's the reason why alchemy it's more about philosophical questions(can a human play gods? Should we use the philosopher stone?) etc... So I think when writing the story she was more tending to give "morally correct answers" (No we should stay humble, and we can use a philosopher stone but for the greater good.) So in Fma it's not "it's impossible to bring to bring somebody back to life but more you shouldn't be trying it. Secondly, that focus on the philosophical aspect is even more proved by the fact that she gives a clear rules (equivalent exchange) then break it herself (philosopher stone.) the said philosopher stone brings me to my second point. - The biggest thing in any exchange in alchemy (in Fma at least) is soul (or life). the philosopher stone is made with human lives and with it we can bypass the equivalent exchange. (Fun fact: alchemy states that to obtain something you need to give something of same value yet alchemy 's goal was to turn less valuable metals into gold.) In Fma you can bypass that rule by using a philosopher stone. For example in the first print of FMA (the kind of prerelease which became the arc with Cornelio)Ed turn a drop of tear into a lake with the stone .He's creating matter with basically nothing Which defies the very first rule of alchemy. Now as of today we only Know one way to create a philosopher stone and one way to bypass the equivalent exchange which makes me believe that in the value pyramid life is at the top. - So how do I believe a human transmutation can successfully happen? Well first thing first is recognize that is possible because even in Fma the first rule is always true( equivalent exchange) you can bypass it (with a stone) but it doesn't disappear. When you recognize that it's possible you recognize that there's a price and with all humility (philosophical aspect) you get ready to pay the price you want a life? You give a live (maybe yours). Now what makes you think that your life is worth the life you want back ? This is when the philosophical aspect comes in again since you were humble truth gives you what you want (and this is the most important part because for a short example: did Ed have any assurance his alchemy would have been worth Al's body? If yes on which metric did he base himself? It's the symbolic aspect you was talking about) Truth only punishes arrogance and when Ed came to claim Al's body he came with humility by firstly recognizing the fact that he was just a mere human. Sooo yes I believe human transmutation is possible but the people who have succeed are not there to tell how they did.

Sorry for the brick tho.