Here is an interesting thread that discusses how the IC could benefit from zk proofs.
My takeaway is that zk proofs enhance security and can enable novel single node trustless computations, but these use cases seem quite niche at the moment.
They play a more prominent role in the Ethereum ecosystem, because they seem to be used as a substitute for subnets + chain key in order to scale.
Of course, zk proofs are just one type of validity proofs. According to this post, the IC’s native threshold signatures are another type.
In short, I feel like other blockchains are playing catch-up but who knows…