$5 is a hardly possible scenario in the observable future taking into consideration current global cryptomarket conditions, XRP circulating supply and its current MC. It is possibly only if the cryptomarket MC approaches to or exceeds $1 trillion, then all assets incl XRP will experience huge speculative price spikes.
But, XRP aims to be the officially recognized asset massively used by banks that means a necessity to evade a price volatility and to be less speculative asset. If XRP will be widely used by leading banks it is possible that XRP will leave the cryptomarket to opearate in legally stable and friendly regulated environment.
I agree with you, Ripple is not viable to reach 5$ because of the fact that their platform is now used for the improvement of the banking system and more banks are using this kind of technology, that is why ripple team are busy to improve their blockchain technology not on XRP tokens because they can generate good income with the application used by the bank, besides XRP tokens is not mineable it can be created with no limits and therefore it can be manipulated.