It has to be said. Its common sense. There are thousands of coins. Scamcoin, losercoin, Shiba coin. All real coins btw.
Yes there will be a couple coins that are very valuable in a couple years but the vast majority of them will be worthless.
Only coins that do things will be valuable. Coins that you have that are just there to hopefully go up on value so you can profit will be worthless.
Its like the dot com boom. You are betting on websites. Which website is going to get the most visitors. Most died.
Some coins even died even before they launch even on their ICO or crowdfunding stage, there are many HYIP types of coins launch on a daily because of the HYIP smart contract so check if the coin you are holding is one of them, so many developers are only thinking on how to scam you only trust coins with a proven worth in the market.