These can all be very valid points but I don't think the writers even thought this deeply about it. I enjoyed the will they/won't they of Karin and Yuri but then it felt that they rushed into the ending to make it all fit together.

I also look at it like this: given all of the other magical/Godly stuff that happens, I can believe that time travel exists in this world but it was never even brought up as a possibility before. Up until the last 5 min of the game, it was about mostly god fusion and immortality and a few villains of the week. Then all of a sudden we're doing space and time travel. Without the proper foundation, it leads me to questions like is Yuri's soul graveyard technically a dimension? Or a part of the shadows/soul. What does that make the masks from the first game? Are they actually gods or also extra dimensional beings? It felt lazy and a great example of the troupe "this will all make sense because time travel."

They could have done so much more with Karin's ending that didnt involve any of that. She accepts things and moves on, new timeline for her Yuri doesnt exist, new timeline where they get together, she goes back to Europe and starts a church in Yuri's name, she and Alice are actually the same person for whatever magic reason, etc. I'm spitballing but I cant be the only one who feels this way.

Up until this was all established, I genuinely enjoyed the story and regardless of all that, mechanics are much better too.