The problem with a pure researcher becoming an insta-billionaire is two-fold:
1. Few single ideas are worth a billion dollars*.
2. Most billion dollar ideas and most researchers in general require funding/support. As such, individuals rarely ever own their billion dollar research.
*Though not technically researchers, the computer revolution is a big/notable exception to this (depending on how you look at it). Major companies came up with a lot of the foundational ideas, but collectively failed to realize what they were sitting on. Guys like Bill Gates and Steve Jobs became mega-rich captains of industry almost entirely because the existing corporations ignored them when they walked away with those ideas. If the big corporate players were paying better attention, we wouldn't have Apple and Microsoft, only Xerox and IBM.