It seems that everyone is assuming people are singing unaccompanied, and probably solo.
What about when there is a group with instruments which need to be in harmony with each other, literally "off the same songsheet". Thanks to the so-called folk process there are many variations in the melody as well as the chords for any song.

As a bit of an aside, how is Joe Offer getting on with his ukulele? Here in England there has been a significant growth in ukulele groups (and community choirs) at the same time as folk clubs have declined. There can be between 10 and 50 people playing together, possibly 20 songs in an evening from songbooks containing up to a hundred songs.

so, back on topic, should everyone hammer away doing their own thing, or not be allowed to play until they have learnt the tune off by heart, or is it acceptable to have the songsheets on music stands? There's a lot of words to learn, plus the "right" chords, for people with no previous musical training if they can't have the safety net.