A lot of law is adjudicated based on the intent, not the black-and-white definition. Proxying your traffic thru a friend's house (VPS in another location, etc) would be considered a "VPN" by a court. Definitional hacks, for the most part, don't fly with judges.

To handle the matter technically Utah would need a "great firewall of Utah" and a legislative mandate that all ISPs route thru it. Somehow they'd have to factor-in signals from cellular sites neighboring states and satellites.

This requires a lot of extra work though, and extra work is downward pressure on the behavior (underage people looking at pornography) that the state of Utah is trying to exert downward pressure on.

The inability to immediately and perfectly eliminate a behavior is not a good enough reason to be against any attempt to eliminate that behavior.

Yes but isn't it suspicious that all your traffic goes to the friend's house and not to Facebook and Reddit? If you claim it is not a VPN does it mean your friend is providing illegal unlicensed hosting? That's even worse.