How Do PoS Systems Mitigate the 51% Attack Risk Differently than PoW?

In a PoS system, a 51% attack requires an attacker to acquire 51% of the total staked cryptocurrency, which is extremely expensive and logistically difficult. More importantly, PoS protocols often have a 'slashing' mechanism.

If a validator attempts a malicious act like a double-spend, their staked collateral is automatically confiscated. This economic deterrent makes the attack unprofitable and highly risky, unlike PoW where the attacker only loses electricity costs.