The Washington Post looked at the 90 most visited porn sites based on UK visitor data from Similarweb. Of the 90 total sites, 14 hadn't yet deployed 'scan your face' age checks. The publication found that while traffic from British IP addresses to sites requiring age verification had cratered, the 14 sites without age checks "have been rewarded with a flood of traffic" from UK-based users.
It's worth noting that VPN usage might distort the the location data of users. Still, such a surge of traffic likely brings with it a surge in income in the form of ad-revenue. Ofcom, the UK's government-approved regulatory communications office overseeing everything from TV to the internet, may have something to say about that though. Meanwhile, sites that comply with the rules are not only losing out on ad-revenue, but are also expected to pay for the legally required age verification services on top.
The UK regulator is already investigating "four companies which collectively run 34 pornography sites" on the grounds of whether the "providers have highly effective age checks in place to protect children from encountering pornography." That means that the days of a web traffic feeding frenzy for porn sites flouting the Online Safety Act's age verification requirements could be numbered—well, if Ofcom can do anything about the clone and mirror sites that will inevitably crop up.