Just to entertain the OPs wild assertion, if for any reason Bitcoin were to falter, it would logically fall to the number 2 coin on the market cap to be the stand-in replacement... that would be Litecoin.
But who knows, if Monero continues to stick around and prove itself...
I agree that LTC is #2 right now. But if BTC does fail it will probably lead to the failure of all coins with a similar codebase. For that reason something different may rise to the top