...THEN add on top that a room full of strangers waiting to be entertained. AND while playing something correctly, also be entertaining to watch.
I think its pretty fair to say that a musician that plays out live should be "ranked" higher than a Yousician, just as a target range shooter is on a lower level than a combat zone sharp shooter.
"Room full of strangers" is just one of NUMEROUS situations that a real musician encounters while playing live. And those NUMEROUS situations make the true musician.
There is a HUGE GAP (IMHO) between playing along to a MIXED, PERFECTED, and RECORDED song that ALREADY sounds good (with or without you), and
articulating that bass-line alone, with all those "nasty" dynamic, tone, sound, articulation, technique, etc... issues LIVE in each and every bar/measure while trying to fit it with the other rhythm section musicians in each and every (always different) environment, etc...