We don't preemptively test everyone for lead either!
This is true, although I would prefer to still test everyone for plausibly important things to feed data analysts who might eventually discover something useful.
I'd love for that to be true, but there's a good chance that in doing broad tests you are incurring costs (both to patient health and cost [whether paid by patient, gov, or insurance company]) without getting anything beyond noisy data without useful signal
That's a lot of blood draws to ask of people, for something that doesn't even have a hypothesis.
There are studies like the UK biobank that are trying to collect longitudinal information about a huge number of people, but they're volunteers.
Related PSA: If you do a lot of target shooting, especially with indoor ranges, it's worth asking your doctor to occasionally test your lead exposure.
The people vested in using lead in fuel said so out of profit motive, but it seems lead was widely known to be harmful for hundreads of years [0] before it was using it fuel.