The entire film is a bit of a mess, but there are three specific parts :-

The Zemeckis Cube : how does this work in an multiplayer online game?

People running round streets with VR helmets : how do they not get run over more?

Shutting down The OASIS two days a week : people get married without meeting. Does this mean for two days a week you don’t get to see your spouse? Isn’t that a truly shitty thing to do to someone?