Maybe it has something to do with what the EPA considers as “hazardous” levels.
Some of the numbers that I’ve seen would be low that you would have to drink an entire lake’s worth of water for the levels of lead in your system to reach maybe a problematic level.
The official government line is that NO amount of lead is safe to consume.
For the most part this is a non-issue because years of hard water scale have built-up on the inside of these lead pipes, so the water no longer makes direct contact with the lead.
The chemistry change in Flint caused corrosion, which undid this.