To me it more so felt like she was spared rather than triumph over it but I do kind of understand where you're coming from

Could you please link a source that says that shows a case where DID is present without trauma occuring during childhood? I have been trying to find cases where it was and have also seen some content creators who have DID themselves who said that you need to have trauma to have DID. I apologize if I came off as arrogant but I simply have not been able to find evidence that shows that people can have DID without trauma

That didn't really look like it to me since the beast was more so portrayed as this unstoppable force to me who just spared the protagonist since she was also a victim of trauma and he believed people who endured trauma to be better (the beast also literally took two shot gun shots to the chest from approximately 2-3m or so and just sorta ended up with minor injuries afterwards)

To be fair, I didn't have any good expectations going into the movie because an old friend of mine who I used to game with told me that the movie is laughably bad due to how it represented DID (he himself has the disorder). I will however acknowledge that James McAvoy did do a good job with his acting. I guess my biggest issue is the writing

It is a disorder that is formed during childhood as a trauma response according to all of the research material I was presented with in high school, alters however aren't always formed through trauma but that is when the original trauma that caused DID in the first place already occurred

I did like his acting but the writing on the other hand is my biggest complaint about the entire movie honestly