Can VPN/DNS providers independently market their services, if content providers cannot advertise VPN providers?

> "content that encourages use of VPNs to get around age checks"

I think "...to get around age checks" is controlling. It isn't illegal to promote VPN's in that country; it's illegal to promote their usefulness in circumventing other laws.

The law reads like it applies to platforms required to do the checks rather than third party service providers.

* https://legislation.gov.uk/ukpga/2023/50/contents

Which section of the Online Safety Act 2023 is that in, please?