The problem with the DPIA requirement is that organizations have to make a judgment call about risk, and regulators have the authority to disagree with that judgment after the fact.
That creates a structure where organizations either:
Option A: Do DPIAs conservatively. If you DPIA everything that might be high-risk, you are over-DPIAing, but you are also safe.
Option B: Skip DPIAs you think are unnecessary. If you are wrong about the risk level, the lack of DPIA becomes a documented violation.
Most companies choose Option B because DPIAs are expensive and time-consuming.
Then enforcement happens and they wish they had chosen Option A.
Here is what actually counts as high-risk and requires a DPIA:
Automated decision-making that significantly affects individuals (not optional recommendations, but decisions that determine access to services)
Large-scale processing of special category data (health, biometric, genetic)
Systematic monitoring of individuals (continuous tracking, behavioral monitoring)
Profiling or scoring individuals based on personal data (credit scoring, hiring scoring, risk scoring)
Vulnerable populations (children, the elderly, people with disabilities)
Processing that involves tracking location, health, or sensitive behaviors
Combining data sources in ways that create new inferences about individuals
If your processing falls into any of these categories, you probably need a DPIA.
If your legal team has ever said, "I don't think we need a DPIA," you probably need a DPIA.