North Korea would say differently. We're spending tens of billions on a replacement so it is relevant. It's the ultimate insurance policy.
If NK ever actually managed to develop a viable ICBM, the launch facility, research facilities and several other military installations would be obliterated by tactical conventional ordnance. Nay a single nuke would ever land on NK.
They must know this, you'd have to be utterly foaming at the mouth stupid to not realise that if the US NATO etc found out that NK had developed a viable nuke that they would ever let it leave the ground.
The fact that NK, Iran etc continue to develop nuclear weapon technology just show how NATO nations that have nuke is simply not a deterrent, they know we wouldn't use them as it would be game over for millions of innocent people, on with sides.
The utterly useless nukes sit in their silos for decades costing billions that could be spent on far more effective areas that would improve people's lives.