Outside of the US spectrum, there are countries that require all citizens to vote or face fines (Peru for example). I find this interesting, because it's so out of sample compared to the typical political fights within the US about voter registration.
> Outside of the US spectrum, there are countries that require all citizens to vote or face fines (Peru for example).
Right, but even for Peruvians, you show up at the both, make your vote and leave, that's it. No thresholds for registering or other stuff, just you and your ID making a vote, even when outside the country. It again makes the US system seem intentionally designed to make less people vote.
This is also seen in the actual voting process itself. Stories about Americans having to stand in the scorching sun for hours are just absolutely mind-boggling to me: you should expect everyone to vote, and provide enough capacity for everyone to cast a vote during their daily commute or grocery trip without a significant delay!
If a bunch of politicians can make voting quasi-impossible for certain groups of people by meddling with their polling stations, then you don't have a functioning democracy.
Australia has both compulsory voting, like Peru, and a separate electoral roll that you have to (and must) apply to get on, like the US. It's not a US thing, it's a common law anglosphere thing.
A website to register doesn't prove it's easy. Texas has one of those too, but obviously it's not proof of it being easy since we're here discussing it.
But I'll give you the benefit of the doubt and assume it's actually easy in Australia. That still doesn't really explain why it's necessary.
It's necessary because we have elections with geographically based electorates, so your address determines which ballot you should receive (and so they know how to fairly resize the electorates). So you need to tell them somehow where you live. Also, the roll of voters has to be printed out many times to use at "check-in" on voting day, so you need to tell them in advance of this printing. They need consistent rolls because after the election they reconcile the various copies after the election to question/fine people who either didn't vote or voted more than once.
For people not on the roll, there is a special secondary method of voting called a declaration vote that allows you e.g. to vote even if you haven't enrolled. But this process wouldn't scale very well - these votes aren't counted for days after as they need to check the details you declared - and is intended as a safety net.