How Does Proof-of-Stake (PoS) Achieve Consensus without a Difficulty Adjustment Mechanism?

Proof-of-Stake achieves consensus by having validators "stake" their coins to participate in block creation and validation. Instead of competing via computational power, validators are selected pseudo-randomly based on the size of their stake and other factors.

The network's security is derived from the economic cost of attacking the network (the value of the staked coins), not from a variable mining difficulty.