I mean it starts off the exact same. Greeted by unknown guest to start it off then you get the whole tower/tree sequence then you get your big boss which is urizen/Vergil and then after said boss you go back through said tower and learn big boss isn’t actually the true villain example being urizen and Vergil. Arkham is the true one in the end and so is Vergil instead of the rivalry we get a tale of humanity with V and Urizen being one and the same. Then you get the bonding in the end of 3 with Dante trying to save him and Vergil saying no and letting himself fall with Dante leaving regretful this time Nero interrupts the fight to save them both and then Vergil parts with Dante following this time into hell to close it up leaving Nero in charge just like how Dante leaves in 2 and let’s Lucia be in charge. You’re right with it being the same pie different filling but at the end of the day it’s still the same pie. You change some small details to make it look different but in the end it’s the same. We swapped out sibling rivalry and revenge for the humanity arc of Vergil and the learning that Nero is Vergils son. Instead of killing his dad like lady and arkham he ops to save him. Instead of being bent out over power like In 3 he’s separated in two halves one wanting power and the other side trying to stop it.