With what I can can see here— the room is great without & I don’t think it would add anything. Now if every other room in the house has a special (not minimal builder) crown, and this one is the outlier, then maybe I’d add it for consistency even if the room didn’t need it.

Crown would be pretty but not necessary. If you decide to do it then consider all the other adjacent spaces too, especially if they are visible from this room.

I see crown moulding adding nothing to that room, looks fine as is.

IMO it would not add anything to the space and the wall with the window IMO would not work with crown. Why this choice would be my qestion if you were my client.Your space looks modern so not sure . For me the cluttered bookshelves would be a big deal and the fact you have that space beside the TV makes me wonder the TV too high above the FPI would remove the shlves keep the bottom cabine mount the TV on an ariculating arm above the low cabinet wall mount at the proper viewing height and hang the art above the TV. Then add some color.