"it's just a matter of time before RSA offers zero security" This is not the only possible outcome. Scalable quantum computing could turn out to be impractical

"it's just a matter of time before RSA offers zero security" This is not the only possible outcome. Scalable quantum computing could turn out to be impractical due to cost. Or new physics could be found that rules out scalable quantum computing. Personally, I find both of these outcomes unlikely, the second more than the first, but they do exist.