There are a handful of sequencing-based genetic tests that have achieved fairly wide penetration; NIPT and cancer panels are probably the best examples.

However, if the question is why whole-genome sequencing has not gained wider clinical usage, I think the answer is less about reimbursement, and more the fact that there are just very few clinically compelling reasons to sequence a whole human genome.

Then there is the fact that although we have ostensibly achieved the fabled "$1000 whole genome" that was touted as the tipping point for clinical acceptance, that was really more of a publicity stunt by Illumina. In reality a clinical-grade WGS still costs a multiple of $1000 (see, e.g., https://bmchealthservres.biomedcentral.com/articles/10.1186/...). The Moore's Law-like cost reductions of genome sequencing are a bit of a myth at the present time; in practice Illumina has a monopoly on the technology used for clinical WGS, and therefore they have a great deal of influence over the effective cost of sequencing.