The only time I lived in a house with an open plan room including the kitchen, we all hated it.
If you were watching tv & someone put the kettle on, you couldn't hear the tv, if someone cooked something, the smell was everywhere long after the food was gone.
Would you put your kitchen bin in your living room?
That's open plan living for you.
Do you have a dog or cat with food bowls you'd have on the kitchen floor?
Now they will be in the living room.
I've been to houses where they had a litter tray in the kitchen, with open plan cat litter can end up in your living room.
Sometimes, what you want is a different room, e.g you & your friends are in the one room having a chat, your other half is in a different room having a chat instead of always having to be right on top of each other.
Or sometimes one of you wants to listen to loud music/a film & the other wants to chat - open plan removes that option unless you have a second living room.
Guests want to stay & you usually put some of them up in the living room?
Now they will be in the kitchen.
Heating is also more expensive.
I would never do it again.
Spent so much time in my bedroom in that little house, because there was nowhere to go downstairs that was away from everyone else.