Personal Statement

Just make sure you speak about them in equal lengths and of course, to include extracurricular stuff too.

In the case of joint honours applications it is usually best to exclude any extra curricular activities to ensure there's enough space to cover all subjects fully (and mention subject relevant super curricular activities)

Really? When I first applied, I spoke about Language and Literature aspects. Then I briefly spoke about being on the school council, prom committee, etc in a few lines. Got accepted to all 5.

I then changed unis and applied again to do a different joints honors and still did the same thing. But then spoke about how I was a student rep at the first uni. I still go all my offers (apart from one cause I didn't meet the A-level grades).

I think you'll have enough to say if you know how to say it. I managed to talk about 6 different aspects between the subjects in each application.

It will vary a lot between subjects - with english lit/lang courses the admissions is likely to be managed within the same English department. For PE/PPE courses admissions is often split between 2/3 departments or even faculties - or will be managed by the philosophy dept at one university and the econ dept at another. Not devoting sufficient space to talking about all the subjects covered is risking a rejection from an admissions tutor who thinks you don't understand what you're applying for.

My 2nd application was Literature and Philosophy which are two very different subjects.

However, if I didn't have any extracurricular activities, then clearly it makes sense to write about the subjects. But if you do, surely it's a good thing to write about?

I just find it hard to believe to not talk about it it's useful, especially important stuff. Not like hobbies aha.

Academics are people who have taken a degree, a masters, a PhD and then dedicated their professional life to the study and teaching of a subject - they're not generally interested in student's activities outside of academic interests.

It's unlikely that a PS will ever result in a rejection (apart from in a few specific courses like health/medical courses and teaching/social work). All admissions staff are looking for in a PS is
a) the applicant understands what they're applying for (this is the risk with combined honours if your PS is heavily weighted one way and hits the desk of an academic from the missing/skimmed over subject)
b) the applicant has the motivation and interest to stick out 3+ years of studying the course (again - a risk if a multi-subject PS is too light on one subject)
c) the applicant has the necessary skills to succeed on the course (for most courses (aside from the health/education/social work examples above) this is demonstrated through the academic qualifications and so isn't necessary to spell out in the PS.

In the case of the OP their application could end up on the Economics desk at Bristol or the Philosophy desk at Southampton or a joint honours desk at Leeds.

Extra currics would be fine to add in IF the OP has space - but they're not essential and could risk crowding out content that would be essential for one or more of the OPs choices.

You don't need to break it down for me.

I find it extremely contradicting you say this but most schools say it's important to put extra stuff you. And I doubt it will be a crime or hurt to do this.

But I'm not going to sit here and argue whether it's a good idea or not. It never hurt me, and I'm sure it doesn't hurt the thousands who do it each and every year.

Each to there own love.