While your observations on the lack of connection are absolutely on point, but even from a performance POV the dev-rishita pairing lack the chemistry you would expect from someone playing a couple deep in love.
The romance seems forced and the actors uncomfortable, in stark contrast with the other couple.
Shiva and Raavi have a natural chemistry and easy comradeship.
They are all kinds of adorable together.
Even when they fight, you can feel the crackling electricity in the air... Or maybe I'm just fangirling 😅
My point is even when I didn't know the premises of the show (I only recently started watching the series) I still thought Dev-rishita didn't seem like a crazy-in-love couple.
It just feels very inorganic to me ...
But hey! That's just me. I could be completely off the mark😕