[icegreentea2]

It's the combination of density and cost increase that's the problem. I don't have the actual N3 numbers, but taking the original example, if you get 30% increased transistor density, but your cost per area goes up 40%, then as a customer you're not in a great position - you're still paying more per transistor.

While there are still other benefits to gain from a new node and increased density (despite the cost increase), if your cost per transistor goes up, it limits where you might want to use the new node (particularly in value sensitive parts of the market).

There's been a long-term trend towards this point - the cost of a new node (the blend of developing it, implementing a design in it, and cost per transistor) has been spiralling up for like a decade+. These are the same pressures that has caused the consolidation around Intel/TSMC/Samsung(ish) in the bleeding edge.