My buddy Dave does this all the time (last-minute dinner plans are the worst). We once had three separate group chats going because he couldn't decide on a pizza topping. It got so bad we just ordered without him, and he showed up anyway. Some people just live in their own time zone.
That idea of "living in their own time zone" isn't always a problem in my view. Some friends thrive on loose plans because it takes the pressure off perfect timing. It just makes hangouts feel more easygoing when things aren't set in stone.
My old roommate was like that. We'd have movie night at 8, and he'd still be at the grocery store at 8:30 deciding on chips. I started setting a hard internal deadline. If I didn't hear back by Thursday, I made my own Friday plans. It saved my sanity. @kimr74's pizza story is a perfect example of why you sometimes have to pull the trigger without them.