Why are pharmaceutical companies moving away from large scale trials?

Pharmaceutical companies are moving away from traditional large-scale, one-size-fits-all clinical trials due to escalating costs, scientific shifts toward targeted therapies, and structural bottlenecks. Developing a single traditional drug can cost hundreds of millions of dollars. Large-scale trials suffer from chronic recruitment, retention, and site-activation delays, making massive footprints financially unsustainable. Companies are heavily shifting focus toward oncology, genetic disorders, and orphan diseases (affecting small patient populations) rather than mass-market chronic conditions like heart disease or diabetes. Studying thousands of patients in massive trials is unnecessary or impossible for ultra-rare conditions.