Actually Safemoon, Algo, Shiba Inu and Ada are included in the category of good investments, but because of the use of little, slow movement, making the coin stagnant, but we do not know what kind of coin this will be in the future, considering cryoto is difficult to predict at this time.
BNB, Solana and Metik are stable coins that are in the top 20, trading volume can also be said to be large, demand and spending are still very stable, so these coins are able to be in a safe position.
I think you need to find out what stable coins are. it is true that BNB, MATIC and SOL are included in the top 20 altoins but these altcoins are not included in stable coins because the price of these altcoins can go up or down quickly. Talking about long term investment nothing is safer than investing in the top 20 altcoins because they have a large daily volume and a large community.