It's okay to have an opinion about a particular artist or style of music, and it's understandable if you don't enjoy Adele or Billie Eilish's singing style. However, it's important to remember that musical tastes are subjective, and what one person likes or dislikes is a matter of personal preference.
Both Adele and Billie Eilish have achieved significant commercial success and critical acclaim for their music, which suggests that many people do enjoy their style and appreciate their talent. However, this doesn't mean that everyone has to like them or that their music is objectively "good" or "bad."
It's okay to have a different opinion, and you should feel free to express it, but it's also important to be respectful of others who may enjoy their music and to avoid dismissing it outright as "terrible" or "dead." Ultimately, music is a diverse and subjective art form that has the power to evoke strong emotions and connect people in different ways.