Yeah, I’m imagining someone like my husband who has several issues with his spine. Or my SIL who recently visited WDW with us and broke one of her vertebra the year before.
For people over 40, 50, 60+ years old, chronic back issues are very common.
So the person who showed up early cannot sit down for a minutes lest they give the wrong impression to other people?
Again, if the view is that important to a party then they should advocate for themselves.
I’ve watched dozens of parades and shows like Harmonious from behind other people and never once expected them not to change position. In those cases I chose not to come early knowing I’d survive an imperfect view.

Am I really supposed to warn everybody who comes behind us that one or more of us may change position at showtime? Each and every time? Or we’re the bad guy?