You're assuming that associations to blocks of linked genotype is the end of the story. Yes, an association to a phenotype using data like that sourced from 23

You're assuming that associations to blocks of linked genotype is the end of the story. Yes, an association to a phenotype using data like that sourced from 23&me only generally points in the direction of the genes and snvs which cause alterations in phenotype, but that is just a stepping stone. It narrows down the search space to about 1-2% of the genome, which then follow up studies can fine map. Using high resolution data, such as whole-genome or exome sequence, you can then pinpoint protein-coding changes which alter phenotype. This is what a lot of people are doing right now, using the last decade of GWAS results to fine map using WGS. If you discover exactly how the machine breaks, it is a lot easier to fix it, or at least prevent it from getting broken in the first place. It is not a simple as flipping one switch, and it is an incremental 'boring' process, but the potential to better understand disease today and in the future is worth its weight in gold.