This ultimately boils down into "Why should we use cryptocurrencies when fiat currencies already exist?"
Having full control of our money
Most people saves their money on banks or some kind of bank (like paypal you mentioned). This was the most secure way to store our monetary value before blockchains come around. Unfortunately, banks need to make like any businesses. They gamble money we save on them all the time by lending them to other people who may or may not be able to pay back. Banks even gamble with money they don't have! (https://www.investopedia.com/terms/f/fractionalreservebanking.asp) When they play with our money, what's stopping them from using the money to invest or fund shady things we may not agree with?
Banks theoretically are able to confiscate your money/asset saved on them anytime they wish whether they goes under by bankruptcy or simply being mean. For example there has been countless example Paypal has denied their user from the funds they own themselves. Banks may also refuse to do transactions for you with your own money for whatever reason.
The only alternative we had was to hold our own money in cash but obviously it's not convenient when we need to pay someone we can't meet physically. Now with the blockchain technology (including Bitcoin obviously) we can put our monetary value there and we know for sure that it's not being moved around by someone else. We have full control of our money in digital form that can be transferred as we wish.
Cheap transaction and fast global transaction settlement time
Sending funds to other countries is expensive if done from a bank account to another bank account directly. Fees for wire transfers averages at 25 USD for outgoing transfers and may take a few days to settle. This is not the case with cryptocurrencies. The current average Bitcoin transaction fee at the time of writing is 43 cents and transactions settles within a few hours at worst. Bitcoin is a particularly sluggish AND expensive blockchain to do transaction, Steem for instance has NO transaction fee and the transaction settles within 3-4 seconds!
People who regularly do transfers with large amount can also take advantage of low transfer fees. Most credit/debit cards (and Paypal) charge percentage fees based on the transfer amount. Paypal for example charges 0.30 USD +2.9% of the transaction amount as fees when you do international transfer. So if you transfer 1000 USD the fee would be 29.30 USD. That's way more expensive compared to just using crytocurrencies. Almost all cryptocurrencies don't care about the transaction amount so whether it's $10 or $1 Million the fee is still around the same.
Protecting our money from the government
Almost all fiat currency has their supplies controlled by government or some kind of central banks or both while for cryptocurrencies has their supply controlled by a consensus run by a lot people so that everyone who use a particular token (like Bitcoin) can expect how much new tokens will be issued. This can change, however any change on blockchain requires consensus to be implemented while government/central banks can over-inflate their currency anytime they want and people won't be able to stop them. We can protect our own monetary value from the government by using cryptocurrencies. This is more relevant for people from third-world countries where the government is extremely corrupt and the volatility of cryptocurrencies matters less.
Using cryptocurrencies also have its drawbacks compared to fiat but i won't write them here as it's not what being questioned. It's not black and white. It's better to do research if you wish to use cryptocurrencies.
Bitcoin is useful as a payment system as opposed to an investment vehicle when you need (pseudo)anonymity, speed, security and if you, shall we say, wish to avoid any Imperial entanglements if you catch my drift. Bitcoin is also useful if you live in a country whose official currency has lost its credibility and become dangerously unstable. In that case, the instability of Bitcoin is of much less concern.
If you want to take control of your own finances without a bank you can. There are too many regulations and it is meant to be yours. the bank tells you what you are allowed to withdraw etc. With Bitcoin you can take it with you and make payments cheaper than the bank anywhere in the world. The banks are scared and feel threatened and don't want people to invest in crypto currencies and that is why we have so much FUD.
Bitcoins are created through the mining process as a sort of payment for allowing your GPU's computing power to be used to process transactions across the Bitcoin network.
PayPal cannot perform this function neither can credit card that's the more reason you should adopt Bitcoin
And secondly Bitcoin is very high and more convenient to adopt thank you
Because the money you have in the bank is not your own, it's the banks. They make insane profits for that convenience while offering a lousy service. Oh, yeah, and when the run on the banks happens they will all go bankrupt. Want to know why? Because of the fractional reserve banking system which gives banks the power to hand out 10x more money in form of loans than they have "in the vault". So, when a big amount of people ask for their money back the banks will just declare bankrupcy. Leaing you with 0 fiat currency in your bank account. And you won't be able to do anything about it.
Unlike in the scenario of banks dealing with your money and making profits, if you have it in cryptocurrency at least you own it. And you can say that its really your own. And no one can take that away from you.
While I wouldn't use bitcoin for everyday transactions as it has proven to be very slow and costly when the load on the network is high, there are many other coins that can be used as a mean of transaction and will be able to handle millions of transactions a day without breakng a sweat. With 0 fees and 3 second transaction times. Wonder about whih magic coin I'm talking about? STEEM :)
Can you transport a million dollars to another country with any of these methods?
Banks do not give you private key for your own money. They can always block your account with absurd reason. This gives you stress and paper work.
Transfering high amount of money in banking system is always problem. They ask about questions about your transfer, source of money, and many more.
You will be treated as a criminal although you are the owner of the money. What a ridiculous situation right.
One day you could wake up and bank would crash and you would try to save your money. If it is over limit of government warranty, you only get that limit of money.
There is a famous quote about banking system
"Give me a gun I will rob a bank,
Give me a bank I will rob the world"