I didnt know thy played that show without a PA system! That explains a lot. Was that the norm back then, and Beatles fans were just on another level of scream?
A bit of both. If you watch any footage of the show, they had no fold back monitors. Ringo was on a riser but couldn’t see any visual cues as to what the other three were actually playing- and yet he kept the beat.
There was no adequate gear for a show like that because it had never been done. The gear didn’t exist. The Beatles were the first.
Add to that the fact that the fans screamed as loud as a jet engine- that must have been a challenging show to play.