The real problem here is money. Clinical trials are expensive, especially ones that need to prove the worth of an entirely new family of treatment. Phages can't be patented in the same way you couldn't patent a giraffe. That means companies have to be very inventive. Some are tweaking the genomes of phages because an edited phage is a patentable phage. There's a Danish company called Sniper Biome that is working in this direction.