There's been no groundswell of opinion, no technically minded authority pushing expert opinion.
The same people lobbying for the online safety act were pushing age verification tools. The government is exceptionally unpopular, even by the standards of already deeply unpopular governments in recent years.
I despair of the situation in the UK. How have we ended up here?
My guess is that the common factor is News Corporation pushing an agenda on behalf of the very, very wealthy.
[1] https://www.reddit.com/r/AustralianPolitics/comments/1nu68je...
It was one of the most agreed with policies at the most recent Federal election.
I hate it as a concept, but at the moment it is all "don't you want children to be protected?", and nothing of substance that people can meaningfully find objectionable (like imgur getting cut off).
I don't think it is particularly a policy of News Corp, although they're happy to run with populist ideas, and more just an issue the Labor party thought they could wedge the Liberals with.