Imgur now blocks several VPNs and have issues loading embedded previews in several fediverse platforms. So instead of using imgur, you could use one of the following alternatives for uploading your images.
https://postimages.org/
https://imgbox.com/
https://imgbb.com/
https://www.imagebam.com/
It’s seems like it’s only a dns level block, so changing to non-isp dns might help you bypass that restriction.
Also in Aus here, using ISP DNS, not blocked. I think what you generally find is that most ISP’s just don’t do the DNS blocks, even if they’re required to. Like you said, it’s very easily circumvented and also it just doesn’t lead to any measurable outcome other than the ISP customer’s dissatisfaction in some cases. It’s probably more profitable to retain the customers and deal with whatever regulatory blowback.