Yeah the weird thing is, despite being easy to circumvent these sort of measures are often very effective! So long as using a VPN requires any baseline of knowledge, technical skill and effort, I expect 90%+ of criminals won't do it.
I've been nursing a theory for a long time that modern society has an accidental saving grace. And that is, if you're competent, its usually better to just not commit crime. Think about it - any criminal can learn lockpicking today via the internet, but few do. Why? Because if you're capable of investing time and energy into honing a skill, you may as well do something above board. Don't break and enter - become a locksmith instead. Don't manage a team of criminals - become a manager at a company. It pays better. Its less risky. There's more services and social support available. You won't go to jail. You can have friends who aren't criminals.
And because of that the people who are left committing the vast majority of crime do so in part because they're not good at long term planning. Which is something law enforcement takes complete advantage of. So, almost no petty criminals are going to know about VPNs. They aren't going to commit to a monthly subscription to a VPN provider. They won't set up a PP2P tunnel on their phone and laptop. Why? Again because if they knew to do that sort of stuff they could probably hold down a stable job in low level tech support.
Obviously there's exceptions to this, but the bread and butter of law enforcement isn't bank heists. Its someone who's drunk. Its someone who smashed a window and stole some money because they want to get high. Or stole a phone out of someone's hand and ran off with it. Or went out with the boys to beat someone up "who had it coming".
When the (then) Australian minister for communication introduced record keeping laws for ISPs he told people they can bypass it a number of ways. Lots of people were confused by that - but it makes sense. The aim isn't to record data from us, or from our community. They don't care about taxpayers who are gainfully employed. The point is to make it easier to catch that asshole who beat up his girlfriend then bragged about it to his friends on facebook.
And as a result, probably the most annoying thing we can do for law enforcement is introduce apps like Signal and the TOR browser. Stuff that makes it dead simple for anyone to maintain their privacy - you just have to use a different messenger.
(Edit: Re-watched the interview where Turnbull described how to bypass the retention bill and he wasn't as enthusiastic as I remember.)