This is more or less true, but what the ECHR/HRA does is place a very strong presumption at the heart of UK law that the government of the day will not seek to violate the rights granted under the ECHR. In practice, this means the courts will go to great lengths to interpret the law in line with them, even if it involving reading them in ways that is not readily apparent solely from the text of the Act, before resorting to a declaration of incompatibility. Per the House of Lords:

> In accordance with the will of Parliament as reflected in [the HRA] it will sometimes be necessary to adopt an interpretation which linguistically may appear strained. The techniques to be used will not only involve the reading down of express language in a statute but also the implication of provisions. A declaration of incompatibility is a measure of last resort. [2001] UKHL 25 at 44

You can see similar in R. vs Lambert [2001] UKHL 37 (e.g. at 42). The Court was willing to read a requirement that that the defence must prove a defence as merely requiring that the defence provide sufficient evidence to that effect.

It also provides a degree of political scrutiny - few governments are going to want the courts declaring that they are failing in their human rights obligations, and so even if it does not prevent them from doing so, it provides a very strong incentive to not do so.

This is analogous to judgements made through the ECJ - they only have more legal teeth because A) Parliament has (by the EU treaties) granted them presumed superiority to UK law and B) the EU can take direct actions against the UK because they are a Member State. For the former, there is very little, legally speaking, to prevent the UK government from overriding that presumption and acting counter to their EU obligations (much as it is possible to deliberately set aside the HRA):

> If the time should come when our Parliament deliberately passes an Act with the intention of repudiating the Treaty or any provision in it or intentionally of acting inconsistently with it and says so in express terms then I should have thought that it would be the duty of our courts to follow the statute of our Parliament. Macarthys Ltd v Smith [1980] ECR 1275

Further, that presumption, nor the ability of the EU to take direct actions against the UK, will not continue to exist should the UK continue with leaving the EU. Even if the Charter were retained, the main method of action would be political, rather than having direct effect on UK law and the UK courts. If anything, its scope of action will be less than the ECHR, because it does not an Act analogous to the HRA enabling the courts to make strained re-interpretations of UK law to comply. There would likely also be no ability for British citizens to take cases to the ECJ (which they can do with the ECtHR), so there would be limited external guidance and oversight as to how the rights should apply to the UK context.

IMO, a Bill of Rights would be strictly worse than what is already provided for under the HRA. Because Parliament is sovereign, it is no more immune to the whims of the future governments than the HRA already is. In some ways, directly enumerating rights in UK law may make it slightly _more_ vulnerable - if a future Act of Parliament contradicts one of the rights, the doctrine of implied repeal may apply (the newer Act overwrites the older) and nullify that right. Because the HRA incorporates by reference, and the UK has international obligations they have agreed to regarding them, it is easier for the courts to argue that it cannot have been the will of Parliament to remove rights en masse or act outside the bounds of their international obligations, and interpret the Act in that light. They would be able to require that future Acts must _explicitly_ set aside the rights, much as they have done with EU laws by reference to Treaty obligations (see Macarthys above, or the Factortame series of cases).

In addition, there would be no source of external oversight. Even if the ECtHR is somewhat toothless, it provides external guidance as to how the rights should be utilised, which the UK courts can then apply in their own interpretations. You cannot get that additional layer solely through the application of UK law.

(FWIW - studied law a few years ago, with a focus on human rights/EU law, but never practiced so some of the details/nuances may be lost)