I don't think school's function is job-training. Employers should do that. School should first provide technical training in subjects, (whether academic or vocational) and secondarily provide some kind of "worldliness" (awareness of history, politics, the law, the function of society). Finances in middle-class+ areas should basically come from family. In schools with high working-class representation I see the argument in providing training on this, but I don't think it's unreasonable to expect parents to do their bit here.
I do think English Language should emphasise literacy and composition (iirc it used to be that English Language was mostly composition, crafting argumentative pieces, etc., I prefer that to the current structure) and then critical analysis of text should be built into the literature GCSE instead. I'm fairly satisfied with the content of the maths GCSE though would like some differentiation, being basically adequate for further scientific training.
GCSEs are a memory game because making them focus on understanding would make them substantially harder. I mean no disrespect when I say that most GCSE students do not have a deep understanding of their subject, they mainly learn facts and relate them to contexts. I don't think this is a massive problem - grokking comes at A-level and beyond. Introducing a substantial problem solving component is not in the student's best interests and would cause upheaval - you've seen the reaction when exams incorporate the most minimal unseen components - being accused of setting off-spec on any slight deviation from the rehearsed questions. (see Edexcel maths 2019)
I think the number of students that are excellent thinkers but are limited by poor memory are relatively few - the content of GCSEs is quite light compared to A-level or degree-level. Since I've started university I've become a fan of exams being 3 hours to eliminate time pressure but I think that might be more stressful for students pre-A-level.