You can call VPNs illegal, but you can't enforce it.
You could make them require age verification for example, or you could ban commercial VPN's and only allow self-hosted ones.
Neither is enforceable. You can theoretically detect VPN traffic, but you can't tell if it's commercial or not. Even the detectable part will no longer be true if you make VPNs illegal, as providers will work towards "indetectability". You can have a list of known IPs, but unless the entire world follows you in your ban, that is pointless.
They could also do what Utah did and make it so that you effectively can't access any websites with a VPN
That law existing is more of a demonstration than an actual law, as it is also unenforceable. Sure, you can have a list of known IPs, but that's definitely not reliable and easy to work around.
Most laws about the internet are unenforceable unless you simply turn it off. That's why piracy is still an "issue" despite it costing rights owners a gigantic amount of money and therefore not lacking incentive to deal with. That's why even China and Russia, who are trying to control their network as much as possible, are still unable to enforce their VPN restrictions properly. Even if the US turned fully fascist they wouldn't be able to enforce a VPN ban.
Thank you for the very long and detailed reply! I do understand that our current understanding of spacetime makes it impossible to do interstellar travel.
I have a background in physics, and although I ended up switching to a different field, there is some fundamental aspects of the field that it helped me understand. The most important one is that it is not an absolute truth, it is the best truth we came up with based on our interpretation and modelling of reality. So I am always careful with tossing around words like "impossible".
Yes, all those hard limits make it impossible for our generation, the next, and probably 4, 5, 10 or 20 more down the line to even consider it. I unfortunately do not remember enough of my uni days to give out examples, so perhaps you can help me here... Brilliant minds in the past have proven that some things considered impossible by the understanding of physics at the time were actually possible.
Now, yes, anything with spacetime manipulation today is conjecture and science fiction, and again, I'm not saying we'll be travelling to even the closest neighbouring star system anytime soon. What I am saying is, we don't know that much about spacetime yet. We know some, we have proven some, but not much. My point is: We have found so many ways around impossibilities that I doubt that (if our civilization doesn't collapse under its own collective stupidity) we can't find ways around these ones too, wether it's in 200 or 2000 years.
Edit: Of course there are some things we'll probably never do. We'll probably never go below the absolute 0, we'll probably never go close to the speed of light either. But that doesn't mean we can't work around these hard limits to achieve goals that they are gating.