And you could say that they all wrote the best songs...unlike some groups where one or two members take the credit for most of the output, with Queen all four members were capable of coming up with a huge hit.
But "coming up with a huge hit" is not the same as writing all the best songs. It would be nice to say that they ALL write the best songs... but it's not true. The majority of the music, including most of the big hits, were written by either Mercury or May. Taylor and Deacon came up with a fair few bit hits between them in Queen's main twenty years, but you could still name twenty well-known blockbuster hits by Freddie, and only about three by John Deacon before you have to start resorting to Number 33 hit "Spread Your Wings".

Si.