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.