It really depends on how much people want to get around it. I grew up in Vietnam, where when I was in about year 10 of high school, the government decided to start blocking Facebook. Their block was only DNS, so word quickly spread around the school that you could still access Facebook if you changed your DNS. This was before quad 9 or even Google's quad 8 (the latter came around shortly after, which was a big improvement to how easy this became), so the DNS we ended up using was a difficult specific number to remember and communicate, but even despite that, by the end of the month pretty much everyone in school—from students to teachers—had learnt how to change their DNS to bypass the block.

People always say that piracy is more popular when it's easier than the legal means. And obviously adding a DNS block to pirating is going to increase its difficulty, and increase the relative convenience of legal means. But if the legal means continues getting worse and worse, at some point piracy is going to look more appealing again, and people will figure out how to bypass the DNS block.