I think there's some misinterpretation here. Not staying on in academia after PhD (common/modal) is not the same as not getting to complete a PhD (rare).
In CS/tech, those who exit academia after PhDs get paid $300K-$500K in the industry. I don't think there's any misleading going on.
BTW, your perspective is bizarre.
Not sure where you're getting the idea that PhD candidate attrition is rare. Maybe at MIT where only 20% don't finish (within 10 years -- which is generous), but these are already pre-screened superstars. Most other places converge around 50%.
As for salaries, the median salary for CS PhDs outside academia is $180k. That means a lot are lower and probably aren't working at big tech with full comp pushing them above $300k. [0]
Yes, I'd like to see data on what percentile gets this and breaks even for lost wages from their PhD years. IMHO, it's not fair to generalize this outcome. I could be wrong.