On the contrary, bitcoin has been widely used for international payments and is way more efficient compared to traditional cross-border remittance. According to Mr. Smith, “They use Western Union, traditional banks; It is slow and it is expensive. And there are people that can stop you from sending that money, whether that’s good or bad. With bitcoin, I can send money. It’s fast. It’s cheap. And frankly, no one can stop me.“
Cryptocurrency is volatile! There is always the chance that the market will crash, or that you will face some other catastrophe. Cryptocurrency isn’t a centrally controlled and regulated fiat currency. If you lose a coin, or someone cheats you, or your account gets hacked, there is nothing you can do about it (which is one reason why you want to have 2-factor authentication set-up).

The second reason to buy the most liquid coins is that there are risks of scams. When you purchase Bitcoin you are sure that you will be able to sell it to somebody later. However, when you buy X coin, which is not as liquid and as popular as Bitcoin is, your risks are higher as everything depends in this case on the project, its team, goals, roadmap, background etc.
Investing and especially trading, is a highly skilled task. You need the best equipment, execution and tools. When the market is only going up any fool can make money but that blessed state never lasts long and what is left is an environment requiring focus, skill and discipline. To succeed unlike the devastated cohorts of dotcom and the real estate bubble, you have to work hard at it.
For example, there are cryptocurrencies, such as Litecoin, with the same goal as Bitcoin. In this case, it would be a good idea to compare its market capitalization with Bitcoin. This site ranks coins by market cap. Always be sure to check there when evaluating a new coin. If you notice a large shift in market cap on a certain date, it may be worth it to check for any news that day to see what may have caused it.
Don’t invest blindy. There are people in this world who would sell a blind person a pair of glasses if they could make money. Those same people play in the cryptocurrency markets and use every opportunity to exploit less-informed investors. They’ll tell you what to buy or claim certain coins will moon, just to increase the prices so they can exit. Due to the highly speculative nature of the cryptocurrency markets today, a good investor will always do his or her own research in order to take full responsibility for the potential investment outcome. Information coming from even the best investor is, at best, great information, but never a promise, so you can still get burned.