I always thought that a lot of singers in bands who write their own music and often play an instrument at the same time should focus more. Even in bands that write their own music, it’s not necessarily the singer who writes their lyrics, melodies and chords.
“writing and composing” is a bit broad, anyway. Do you exclusively do covers of other people’s songs where you copy the original singer exactly? If so, cool, that’s pretty hard to do well! If not, you’re writing/composing/improvising vocal parts, and that’s a skill, too.
Can’t deny that there’s a really big difference between late 60s rock and 40/50 rock, though - it’s not really wrong to consider it a new genre, even if it appropriates the name of the older genre.