Students coming in from other systems have had different educations. Overseas students sometimes really struggle with the expectations of a British university essay as they have had a completely different training in writing up research. I am NOT saying that you SHOULD do an epq because it gets you into university or directly helps you get a first. You are emphasising causation above correlation.
I am saying there is a distinct correlation between the student who has developed research skills and passion for their subject and genuinely enjoy sitting in an archive or a library doing deep primary research and those who get a first. In my subject area, doing the above is vital to produce an original research paper that has the potential to receive a first.
You do not have to have done an epq to do the above. Epqs didn’t exist in my day and I was still passionate about research, received a first and went on to a PhD. Doing an epq when you don’t care about the topic (or have been set it by the school), think it’s boring, and you are only doing it because your mum/dad/teacher/sister/uncle told you it would help you get in to university or help you get a first... won’t help you. You are also probably not the sort of student who has the right mindset to get a first in my subject.
However, the student who has relished doing their own research, producing a paper to a more university-style standard and has found a talent for independent research tends to be the same student who flourishes at university. They also have worked on the skills that will help them do better at university so they tend to hit the ground running and receive higher grades even in their first year (ie. causation), compared to the students who are talented and passionate but have only done A Level essays, which they then try to replicate at university and are devastated when their A Level essay structure, methods of using secondary material and ways of forming arguments produce a low 2:1 or 2:2, when at school it would have got them an A.
I ran some essay writing sessions last week with students and asked them how many of them had been taught a PEEL paragraph. Every single one had, apart from the Aussie and French students. Half the class were still relying on them and then wondering why they were criticised for having weak transitions between paragraphs. PEEL paragraphs produce poor essay structures at university, but tend to produce great GCSE and solid A Level essay structures, if you measure that by marks alone. The EPQ won’t correct this, but students tend to be more exploratory in their writing and less fixed to particular structures and models given to them to pass their A Levels.
One-third of marks available in our system is for how you write and present your essays. Students are marked down for incorrect bibliographies. We give students examples of how to write them, but those who are used to doing it are quicker/more accurate/realise the importance without having to lose marks a few times for improper citations.
As such, whilst epqs are no guarantee of receiving a first, we can see both correlation and causation between doing an epq and flourishing at university. There is correlation between doing an epq and being autonomous and passionate as a scholar - and causation in that the skills required for an epq are closer to those required for degree-Level essays, so students tend to be quicker to start getting good results, so are more confident, etc etc.
I am not saying that you have to do an epq to achieve at university. You could go to every writing class, pay attention to how journal articles are researched and presented, experiment with your own research and ways of writing, and go to discuss your feedback with your tutors after your assessments, and get the same outcome; my students who do all of that are also the ones who tend to get a High 2:1 or first. However, it’s often after receiving an initial grade that has disappointed them: those who are resilient crack on with fixing the issue, seek support and move on from A-Level writing methods; those who are less so tend to have an early wobble.