I likely should have read this thread, but way too long for my attention span.
So I will only add, Paul wrote the music to Let it Be in a couple hours. It took a couple of weeks to get the words written. Which is why I vote: lyrics are most important.
Bad example that defies logic. He took weeks to get a mediocre lyric into shape. This tune, as an instrumental, has been covered thousands of times and is a background music staple.
Tons of great songs have terrible lyrics.
Bang a Gong comes to mind immediately.