.... potential replacement for bitcoin. We all thought it was litecoin.
You all thought is was litecoin maybe. Litecoin is so much a clone of Bitcoin such that any fatal flaw in Bitcoin will also be a fatal flaw in litecoin. Litecoin is pointless.
Dislodging Bitcoin is a difficult task but not unachievable. However, currencies like Dogecoin or Litecoin will never be up to the task since they are fundamentally no different from their parent Bitcoin. Only the highly innovative currencies with unique features will be able to take on Bitcoin in the future.