I'm with you. OP must go to weird events or hang out with odd people. No event I've ever gone to had this issue if it wasn't a wedding or birthday party for obvious reasons. The food is obviously there to be eaten and folks are already cutting into dishes ao it makes no logical sense to be scared to cut into a dish especially by the time dessert rolls around. You have literally already cut into so much shirt by that point what's the point of being scared to do the very thing folks are there for in the first place? There isn't a point.

In my family especially it is actually considered rude to do that shit. Kids and elderly eat first and often get their plates made for em even and you shouldn't show up with dishes eaten off there. If anything, if you actually serve good food (maybe OP is going to events that don't perhaps?) you have the opposite problem where you better hurry tf up and get it while it is still there. Folks definitely don't tend to have an issue diving in when it's good.

I can't imagine going to an event and folks are just spending hours staring at the dessert or some shit when every dish has been touched. Sounds like a made up issue or something.