Bitcoin is fast becoming a universally accepted cryptocurrency and truly so, it has established itself as "somewhat" parent coin to the likes of Etheruem, Litecoin, Dogecoin and many others.
Few years ago, some many predicted bitcoin was going to fade away like some other cryptocurrencies but instead of falling off bitcoin has grow stronger and have been widely accepted for transactions.
The biggest breakthrough for bitcoin is seen this year, the coin value has consistently rise and even government of most nations are endorsing and legalising it for transactions.
I would not call it a universal currency. What I would rather say is, right now we do have a lot of countries and the governments still against bitcoins, at the same time, it's hard to pin point their actions for the future, we know what and how they are behaving regarding cryptos right now but we will never predict anything else, they might decide to ban it in the upcoming future.
Bitcoins is perfect, except the Volatility ofcourse, but there are many things that can be used to make it a universal currency, the exchange rates would be much less, the transaction fee would be less plus it would be faster as well, no single county will own it. Things like these are very important to be in a global currency but for the time right now we must focus on *adoption*, universal adoption if I may and wait for it to become a universal currency.