The biggest issue facing bitcoin, is that there's nothing to stop a "bitcoin 2" from entering the market.
Actually, there is. It's called the "first to market" advantage. It's why VHS beat out Betamax in the consumer marketplace even though everyone agreed that Betamax was both a superior format and at least as cheap to mass produce. Anyone can try to replicate Bitcoin, but without a
significant and obvious advantage to users, it's market uptake will never approach Bitcoin's.
VHS didn't win as they were 'first to market' - in fact the whole first to market thing isn't really that big a deal. Apple weren't first to market with MP3 players, smartphones, laptops etc. Google weren't the first online search engine. In fact if you pick pretty much any technology the first to market has vanished into history and is possibly only surviving as a name branded on a successors products.
Just look at the brands around you in your room - how many of them can you genuinely say were first to market?
Just looking at replacements for cash - you got a Diners club card in your wallet?