As someone who grew up playing from the dots, with other musicians, and by ear, saying that one cannot keep a decent rhythm with one whose nose is in a book is uninformed, imo. The art is to watch the other players/singers with the music being available in an unobtrusive way. I used to lead a string quartet that way. we played from memory, at times, but most of the time with the music and no one ever complained about our being out of sync.

Singing in Paltalk, well no one can see, but I do use my book of lyrics. If I am playing an instrument, I play by ear. I don't see any harm in having the lyrics handy and I think it is rather snobby of others who look down their noses at someone who may not have their memorization abilities, or be as old, therefore had more time to learn, or even who may not have enough hours in the day to learn them all, but still loves to sing with others. Last I knew that wasn't a crime. Like RichM, I appreciate people being up front about what they will tolerate, though. And, like BillD, imo, if you have the book, you'd better know the song well enough to sing it properly!