I think if games continue to progress sooner or later they will have voice sliders and lots of options for the player character, so they will only need a few people to voice your PC, but you can make the voice sound the way you want.
Watchdogs: Legion tried something of that sort, with mixed result from what I heard.
Still, that is simplifing voice actors' job quite a lot - they provide far more, then just reading hte lines. Performance is interpreting - timing, putting stress on words, convaying thoughts and emotions. That's the value of VO. You can electorically modify the voice (horror, horror) but the performance will remain the same. You can make a chipmunk out of Geralt, but that won't change the delivery of his lines.
