The OSA has several different parts. This ruling is not concerned with those parts of the OSA which deal with child protection; age verification isn't meaningfully mentioned anywhere in the judgment. Additionally, encyclopedias in the UK have routinely included factual sexual content for many decades -- just pick up an old Britannica for evidence -- without being characterised as pornographic. I don't think the OSA seeks to change that.
The main problem I have with the OSA is that age verification for explicitly pornographic sites exposes users to the very real risks that you mention. However, that's really nothing to do with this ruling, which is instead around the special duties that the OSA imposes on "categorised" services.
The main problem I have with the OSA is that age verification for explicitly pornographic sites exposes users to the very real risks that you mention. However, that's really nothing to do with this ruling, which is instead around the special duties that the OSA imposes on "categorised" services.