If you look at it logically from the point of return on investment.
90% cure (Sof+Riba or Sof+Led) – leaves 10%
90% cure (Sof+Vel) in that 10% leaves 1%
90% cure (Sof+Vel+Vox) in that 1% leaves 0.1%
0.1% of 180 million is “only” 180,000 total patients versus 179,820,000 who could have access to curative medication that already exists.
With ABT-493 3 x better than GS-9857 (Vox) and ABT-530 10 x better than Velpatasvir for all intents and purposes 99.9%+ of people can be cured with existing medications.
The issue we have is not further invention. It’s deployment on an industrial scale.