Some tests not only don’t benefit patients when done without reason, they actually harm them. medical interventions and procedures are often invasive and not without side effects, including pain, severe disability, and death. In many cases the studies you allude to us waiting for have arrived, and they show active harm for many cases where you’d think “why not add a test, what’s the harm”. Unfortunately medicine is still way too complex to reason about without the research to back it.
In my field of nutrition alone, there is tons more we could do to individualize and thus improve the targets for macro and micronutrients, as just one example. RDAs are only a rough starting point (when there is an RDA) as we understand more about individual genetics, food environment, etc. Why is all of medicine just invasive procedures and pharma? I'm not convinced that we somehow just need to sit and wait for some future time before we can jnvest and safely make use of markers over ones life to improve behaviors and health outcomes (for the benefit of an individual and others with similar medical characteristics).
Theres room to debate the degree and depth that we would utilize labs and other measures, but a complete non-starter mentality just leaves health outcomes to blind fate and promotes development of complex conditions much more difficult to unwind.
