ECHR orders banning actions that could cause severe and irreparable harm to an individual. Their judgements should not be overturnable by a single uk politician, who might or might not be acting in good faith, or know anything at all about the situation.
I am not saying what I think about Suella Braverman in particular, ( and I dont think anything good) but whoever is in this position now or in the future, who could be better or worse than SB, should not have the authority to overturn a ECHR decision based on knowledge and experience of many different countries, and assessment of evidence, and likelihood of irreparable harm to an individual.
Who knows, it could be any one of us one day, relying on the ECHR to save us from torture or death. Of course it doesn't matter who it is, it could be anyone. I think it says a lot about SB position of immense privilege that it doesn't seem to occur to her it could one day even be her.