My Politics teacher wrote on her PowerPoint:
The Human Rights Act 1998 doesn't explicitly say that anyone has any rights. The HRA merely requires certain bodies to do certain things in relation to European Convention of Human Rights (ECHR) rights in certain circumstances. The Human Rights Act 1998 doesn't actually incorporate the ECHR rights — the HRA just gives them certain effects in domestic law. I.e. the HRA doesn't make the ECHR rights a substantive part of UK law — the HRA merely requires (among other things) UK courts to interpret UK legislation compatibly with the ECHR when this is possible.
But she doesn't know why. But then why did the UK incorporate EU law by section 2(1) of the repealed European Communities Act 1972 (ECA)? I know the UK exited the EU on January 31st 2020.