Every investor should keep in mind the fact that "no cryptocurrency stays at the top forever." If you want to invest, buy popular coins with the intention of selling them or converting them to bitcoin when their value soars. But, never hodl it for longer than a year or two because anything can happen during that time (such as an altcoin losing its value or fading out totally), leaving you at a loss.
However, people don't just keep tops coins forever, they'll sure try some experience in buying new coins to compare which is more profitable. In a few years from now, changes will come and it was not because of the tough market competition but it is because the mindset of the investors had also changed. What matters for them is profit, not rank as we can't deny that the new project is more profitable but yes, it is too risky as most of them are scams.