Plastic, vapor retarder or nothing?

[Hans G2]

I am going to renovate the kitchen thoroughly, so the floor, drywall, and ceiling will be removed. After some investigation, the construction looks like this today:
Wall from inside: Drywall, 3/4" panel, 5x2 stud wall, 12mm fiberboard, facade brick
Ceiling from inside: Beadboard, 3/4" panel, plastic, insulation

At the ceiling-wall angle, you can see that the plastic in the ceiling hangs down on the inside of the wall panel. It also feels drafty at the ceiling-wall angle, more noticeable when the wind is blowing.

So the question is, should I take the opportunity to put plastic or a vapor barrier behind the drywall while I've opened up the walls? Since the plastic from the ceiling is somewhat visible, it can be taped together to some extent, at least significantly tighter than it is today. Or am I just creating a bigger problem with plastic/vapor barrier on the inside since there is fiberboard further out in the wall?

 

[Oldboy]

It should be fine to install at least a vapour brake. In principle, regular dense construction plastic should also work, but with older houses, there can sometimes be factors that overturn modern methodology. The decisive factor should be if the old solution has worked smoothly without moisture damage for 50 years, then the same solution should work smoothly for the next 50 years as well. It also matters how the interior is executed. With dense materials on the walls, virtually no moisture penetrates the wall, making a waterproofing layer redundant.

Asfaboard is a good material that is moisture open, so it has no problem with a waterproofing layer inside.