$safemoon for example, if you just read the details, you will be astonished that someone actually thinks it's legitimate.
As long as there are naive buyers of these meme tokens, they will exist. Because most of these investors are aiming for high profits at a short period of time. Most of these tokens have no reasons to exist in the first place. They are just created for the hope that they can deceive users and devs gain money. As you noticed, most of them are anonymous team, so yes, they can easily disappear when they got their pockets full. Anyway, they only invest small resources to deploy their project.