As I point out here, even Hyundai doesn't think the Ioniq will be killing anything, much less Prius. Hyundai's own timid sales projections bear that out and what's more, the initial sales are, well, less than even timid.
None of this is to imply the Ioniq is a bad car. I think it has a lot going for it. And, what Hyundai is doing in offering Ioniq in different forms is brilliant. Will it work? Does it work? Sales aside, is it a great car? I can't answer any of these (yet).
Even The Verge says...
Back to my point, neither can the people at The Verge. They don't know the answers. They took some pictures in Geneva and came up with a headline crafted specifically not to tell you much but still get you to click.I'll need to actually drive the thing before we can make any concrete judgements, but given Hyundai's other cars I suspect the Ioniq could provide Toyota quite a run for its money. It'll come to Europe and Korea this year, before possibly coming to the US in 2017.