I for one believe that it is about time that Northern Ireland be integrated with the Republic of Ireland to form one Island Nation. Britain would be a lot better off not having to deal with that issue. But, then again, I am just a dumb American that thinks common sense should prevail.
The problem is that there is a significant number of people in Northern Ireland who desperately want to be part of the UK.
That number is diminishing.
In a generation or two, it will likely be insignificant if a straight line projection happens. Of course, it never does...so we don’t really know what the future holds.
But as I see it, the number of people who built a life around being a UK citizen in Northern Ireland is still way too large to do that, at least not quickly....perhaps a twenty or twenty-five year plan would work and be a commonsense solution (to your point...).
I understand your pragmatic viewpoint. It might be compared, though, with solving the Two China problem by giving China Taiwan. Ah, peace in the region, except for those pesky Taiwanese who don’t want to be controlled by the PRC.
It could be The Troubles redux, a series on constant conflicts wherein, IMHO, a pox is earned on both houses.