When people saw the value of Bitcoin, they also created various altcoins. It will run away after harvesting and have no real value. Although these coins are not reliable, there will be some people who are willing to bet that altcoins can explode. Some people who make a profit from investing in Bitcoin will also choose to invest in altcoins.
In such a messy market, how should we invest in cryptocurrency? What should do with these altcoins?
Although you are right to an extent but at the same time, I do not totally agree with you. In the crypto space nowadays, it is evidently clear that a lot of scammers are around who creates different tokens with no real value but at the same time, there are a lot of projects which are created and of course have good use case hence the reason they keep growing while lasting long term. To back this up, the top 100 coins and tokens on coinmarketcap is a good proof that even though there are useless altcoins, there are still few that are worthwhile.
Also, people who bet that a particular altcoin will explode are people who are looking for those to dump on, and this usually happens with useless tokens; already built projects have no time for such act, instead the team pays more attention on their goals in order to attract more investors.
So in a nut shell, go for good projects and overlook those seeking to scam users through flooding the social media channels with their promotions.