I think there's some misunderstanding here. My suggestion (which Vandal Hearts demonstrates) is that the game should remain isometric. That is, there are parts of the battle where you're scanning the battlefield and choosing what you want to do. This should remain isometric.
However, every time you decide to complete an action, you then have to watch your character complete the animation for that action. This is a good opportunity to get more cinematic.
This is what XCOM 2 does.Some games can get away with being locked in a permanent isometric perspective. I'm not too worried about that though. XCOM is more action-focused and D:OS is more story-focused. That's why I'm more worried about the storytelling. Diablo 3 is another action-focused game (with a good story), and it sticks to a strict isometric perspective even in dialogue.
Watch these players paying close attention to the Diablo 3 story.Baldur's Gate was also strictly isometric, of course, due to limitations at the time and is reputed to have a good story:
yadda, yadda, yadda.
Everyone's favourite example,
the cinematics of Witcher 3 leave absolutely no room for less than your undivided attention. Can you imagine any scene from the Witcher being presented in an isometric format? Of course not. Because he actually has facial expressions. This is the ideal.
Or we could look at Vandal Hearts again. It's 100% isometric, but they make an effort to zoom in when you're performing an action and
stage the dialogue to be as cinematic as possible.
