Sure, maybe, but I’d also say you shouldn’t let the perfect be the enemy of the good.
Yes, we should absolutely have better mental healthcare safety nets. Yes, false positives are probably a pretty common prank.
But this isn’t a zero sum game. This can work on tandem with a therapist/counsellor to try and identify someone before they shoot up a school and get them help. This might let the staff know a kid is struggling with suicidal ideation before they find the kid OD’d on moms sleeping pills.
In an ideal world would this be unnecessary? Absolutely. But we don’t live in that ideal world.
It doesn’t have to not hit pedestrians. It just has to hit less pedestrians than the average human driver.