The real question is "what will destroy crypto" I think it would take a lot more to destroy bitcoin without destroying the rest of crypto than it would to just destroy crypto altogether.

Bitcoin has basically turned into a gold standard at this point. Using it for actual transactions is not really done very much, as other coins provide faster functionality (Litecoin comes to mind).

It is possible that the lightning network for bitcoin will fix that and bring bitcoin back into more of an active usage state (which would have a pretty big impact on other coins), however the gold standard will still be a big part of bitcoin for years to come.

The only way i see bitcoin dying without totally screwing up the rest of the market is if another coin takes over the "gold standard" slot. For this to happen, it would have to accomplish more than just a technical hurdle, it would have to be a change in belief in the general population, and that's really the key to all of this.