There are really a lot of coins like you are looking for, their value can drop by 100% and can be called dead coins. These coins are shitcoins, pump and dump, if you invest in shitcoins cases like this are not too surprising.
Luna's case is different because it's the top coin, it's not like shitcoins are created in a few days and die later. Luna was built by a professional team with high utility and application, I remember correctly, Luna was developed from 2018 until it crashed. It has come a long way, no one would have thought it could collapse so quickly for a top coin with a billion dollar market cap.
Yes you are right about Luna, it's not like every other meme coins out there but it's a project that was created with a bad foundation, every investors should learn from Luna mistake, when your coins are surging either good or shit project always take your profit, never ever fall in love with any altcoin.