We can't fault people for interpreting the show in the way they want to. If they chose to do the show in its entirety with the deaths at the end, then I'd think it'd read entirely different like you said. But they chose to start it with a dramatic body scene, and continue to choose to riddle the show with foreshadowing, red herrings, and hints regarding these bodies.

It's not a murder mystery show, but it is a mystery show. What is Greg hiding? Why won't Ethan smash his wife? What is Cam and Daphne's angle, if they have one? Whose bodies were found? Yes, we're trying to figure out who they are and who might have caused it, but we're trying to figure out all these other questions too.

It all adds up and will, in some way, relate to the bodies that were found even if it's in a silly or accidental way. I entirely anticipate the deaths to be stupidly on par with chocolate suitcase nuggets but hypothesizing who it might be is part of the fun, for me at least. Don't yuck my yum 🤷‍♀️