Trying to build ever-larger aircraft carriers is like vertically scaling using mainframes. The number of uses for these seems to be dwindling, and it's becoming

Trying to build ever-larger aircraft carriers is like vertically scaling using mainframes. The number of uses for these seems to be dwindling, and it's becoming harder to justify the cost and complexity of maintaining this expensive and uncommon hardware. Compare with horizontal scaling, which in this case translates to large numbers of individually-capable units acting in coordination. It's just too damn hard and expensive trying to protect a single valuable target against an ever-increasing number of threats.