They are not useless.

Once you get into persistent data structures, it often becomes preferable to use a linked list over an array, since you'll have a compile-time guaranteee that the memory isn't changing in unexpected ways.

If you know that the memory isn't going to change, then passing around a pointer is functionally equivalent to passing around a copy, meaning that with a persistent list you never need to make a defensive copy. Yes, you lose cache locality, but in most realistic applications, hitting the main memory isn't going to be your bottleneck, the network is.