Please give some reasoning along with your claim. In what way do they suck, in which cases? Do they really need to stop being used? I'm not just being pedanti

Please give some reasoning along with your claim. In what way do they suck, in which cases? Do they really need to stop being used? I'm not just being pedantic. I just haven't had any problems with the concept of passwords as a security measure. Many implementations are flawed, but that is a different manner.