I personally see Bitcoin itself falling apart because it lacks the critical ecash property of untraceability, meaning it is the original non-fungible token. Regardless of how many honest verifiers follow the protocol, it's still possible to build a parallel system that determines which transactions/flows are legitimate or not according to completely different criteria - eg AML. This is happening slowly from both the bottom and the top - from the cryptocurrency industry with "blockchain analysis" and from the incumbent financial system with slowly creeping KYC rules. Right now you can squint, use a mixer, and perhaps a less regulated exchange - just as ten years ago many people blissfully thought the whole thing was "anonymous". But the writing is on the wall. As soon as the more regulated exchanges start commonly rejecting certain wallets based on history, those coins will become worth less. Everyone will be drawn to the attractor of the prevailing parallel rulesets to make sure they're not receiving tainted coins, and the currency will essentially fork.