Open-concept remorse?

We’re renovating (not gutting) a 2-family brownstone (20×55) that has 2 identical floor-through units, and we are really struggling to decide which, if any, walls to remove. Both units are 5 rooms deep (the middle one being the bathroom w/airshaft). Both units still have the original small kitchens in the back left of each floor, right next to a bedroom, and with the front two rooms of each unit being used as a connected living/dining area. Our architect’s first round of schematic drawings show a completely blown out back half of the unit, which keeps the kitchen in its current location, but essentially removes all of the walls to create a very open plan kitchen/kitchen island, dining, living space (and the bedrooms have been moved to the front).

I know it’s the trend these days to remove all the walls, and I understand that light is at a premium in these long brownstones, but having grown up in a house with many rooms, I am concerned that we will regret losing the distinction between different spaces; the feeling of leaving the kitchen and retiring to a living room a fter dinner; the ability to slam a door in anger, or just occupy different parts of the house. Not to mention removing walls means losing all the original detail of door frames, molding, plaster walls, etc. Most of all, I do not want this to feel like a modern condo when we’re done.

I am curious to hear experiences from those who have chosen to either: 1) keep more/most walls and distinct rooms vs. 2) remove lots of walls and create an open plan space. Has anyone had open-concept remorse?

I feel like we are going against the grain in not tearing all the walls down, so I am looking for perspectives/solidarity/encouragement that we can create a warm, light, functional space while still keeping walls (unless we can’t?).