It doesn't matter what good, serious, and promising projects they all were. After 10 years there are only those that have the support of a community, Bitcoin, XRP, Dogecoin, and Litecoin.
But does it matter if your coins is still in the top coins on coinmarketcap, what matters is whether you made profits from your investment or not therefore if you can make profits from memecoins and change your life story as some individuals are doing, why not follow them and try your luck but don't invest more than you can afford to lose as memecoins investment are more as gambling than investing as you don't know what the outcome will be and you'll most likely lose your money.
Most Memecoin projects are pump and dump scans this is the reason you're more likely to lose your money when investing into them therefore if you don't have the ability to let go of your loses don't chase after memecoins and invest into fundamental altcoins as Ethereum that won't disappear with your money but will be active in the market in all conditions developing their Blockchain to make it more better..