How do ZKP-based blockchains handle privacy while remaining verifiable?

Many blockchains struggle to balance transparency with privacy. Fully transparent ledgers expose transaction details, while private systems often raise concerns about trust and verifiability. Recently, blockchains built around zero-knowledge proofs (ZKPs) have been proposed as a way to solve this trade-off.

I’m curious how ZKP-based blockchains validate transactions and state changes without revealing sensitive data, and what practical benefits or limitations this approach has compared to traditional Layer 1 or Layer 2 designs.