Invested on countless shitcoins in the past and currently, most of them have already halted operation and the poor investors are left holding worthless bags on them. There'd be countless crypto out there that would seem legit but if you look closely, they're nothing but another scheme to make money for its devs. I believe that 90% of the existing coins are nothing really special, just a normal copy of some prominent coins with some variations here and there. At the end of the day though, investors would ultimately decide the fate of a coin.
There are certain things that every investor should look for before investing in any coin:
1) First of all look at who is the person or company behind that particular coin. Launching a coin and doing false marketing for the coin is not that much costly. But supporting the coin for years is something that only a person with deep pockets can do.
2) One should also look for the features in the coin and how is it different from the current coins. Finally, new investors should stay away from any coin that has been launched recently like say 1 last one month.