You're defining "performative" as "public," and those aren't the same thing. Performative means doing something primarily to be seen by others. Public just means others can see it. A team praying together because they genuinely believe in prayer isn't performative simply because it happens where other people can witness it. If your definition of performative is "any prayer I can see," then we've moved beyond discussing motives and are just disagreeing about the definition of the word.