I find the term 'immersive' doesn't describe accurately the sense I get from games that absorb/engross me. A film or game can captivate me entirely in third person perspectives and I'm never more engaged with the world by seeing it in a first-person perspective as the aspects that I'm judging while playing are the quality of the environment and such that don't change in either perspective.Third person is less immersive by definition. It's no longer you, it's you watching a character. Immersion is the dumbest argument for third person.
Neither do character dialog interactions make me feel more connected to an in-game world by being in first-person. In fact they can often distract given the limited ability for the playable character to emote in first-person during sequences where they're interacting with other characters (it nearly always comes across as unnatural since we don't see movements in that manner IRL).
With VR on the other hand it would be possible to more fully model such interactions and of course the actual immersion level would be inherently more natural. Otherwise I'm more fond of third-person with third-person dialog and cutscenes, as apart from affording designers more flexibility with animations and cutscenes it also helps those with even mild motion sickness.