I think this is a general misunderstanding of how common law legal systems work.
The extent to which these are or are not generalized is decided by judges based on the merits of individual cases, and while a written law might sound broad the way it's interpreted is up to the accepted precedence.
I suspect a porn site would be ok because it's clearly labelled, and isn't trying to entice kids to engage with it. However if you're social platform deliberately trying to increase engagement with under 18s, and then promoting sexual content to them...
The extent to which these are or are not generalized is decided by judges based on the merits of individual cases, and while a written law might sound broad the way it's interpreted is up to the accepted precedence.
I suspect a porn site would be ok because it's clearly labelled, and isn't trying to entice kids to engage with it. However if you're social platform deliberately trying to increase engagement with under 18s, and then promoting sexual content to them...