Less easily doesn't mean that it can't, just that it is harder to spread through one avenue of infection. You still have large numbers of people congregating and existing in a common space. Railings, bathroom facilities, eating, packing themselves into corridors getting in and out of the stadium. This is ignoring the fact that most did not practice social distancing or wearing masks. If you think social distancing was being actively followed, you were kidding yourself.

The point that jumps out in my head was watching a college championship game, people in stands without a mask to be seen, standing shoulder to shoulder, game is over, and they all crowd the field hugging, kissing, partying.

There were no guidelines actually being followed at these events, not even remotely. In some states, it was even encouraged to not follow guidelines just to thumb their nose at liberals.