There are quite a few things about your posts that worry me. I think I'm right in thinking you are a maths teacher? So possibly an element of bias. As a historian who hated maths with a passion perhaps I can throw my bias in the opposite direction.
Life is not all about earning lots of money - perhaps we should make history a compulsory subject to 18 to teach a broader perspective? Life should be about being fulfilled and doing the things we enjoy. For my DH (whose 7 A levels include 3 different types of maths plus physics and chemistry) algorithms are a source of joy in his working life. I could think of nothing worse and found satisfaction in a career in accountancy that involved meeting lots of different people and trying to sort out their personal finances. In all my years as a tax partner I never once needed to use any maths that I had not learned at primary school. (This is why, contrary to what a PP said upthread, you do not need A level maths to become a chartered accountant.) However the grammatical rigor I learnt taking A level Latin was immensely useful for tackling the seemingly impenetrable depths of the tax legislation. I worked with a very broad range of professionals including bankers, brokers and lawyers and many of those had arts degrees. Not every job in finance is rocket science.
the economy isn’t struggling due to a lack of people with art qualifications.
This is just so wrong. Whilst finance is the biggest contributor to the UK economy, the second is creative arts. Arguably, therefore, we could grow the economy better by focusing on our world beating skills in this area and turning out more people with arts qualifications rather than trying to push reluctant teenagers into STEM. It is also the case that the arts are probably the one area of the economy where human talent and creativity is unlikely to be overtaken by AI. (You can programme the rules for composing a fugue into a robot but the end result will not compare favourably with the Well Tempered Clavier.)
This week we have been looking back on the career of Vivienne Westwood - fashion also contributes well to the UK economy and it is also an area where we are seen as a world leader and as innovators. We wouldn't be there without people who are artistic and in most cases have art qualifications from world leading institutions like St Martin's.
In fact (trying to bring in the balance expected in a history essay) we need a wide range of well educated people across all fields to develop a decent economy. A significant growth field in the UK is computer games development and that needs both computer whizzes and decent graphic artists - I suspect that few games designed exclusively by one or the other would be that good.
What we really need in post 16 education is an acceptance that it takes all sorts and a good hard look at what it is meant to achieve. This ought to be fostering a love of learning one's preferred subjects and laying the foundations for living a fulfilling life. For some that may be a vocational qualification that leads directly into work or a degree apprenticeship, for others it might be an IB type qualification that means they don't need to specialise too early. However, for many teenagers like me, you know what you want to do well before the sixth form. For my husband that was as much STEM as possible and to give up English, which he hated, and for me that was humanities/arts A levels and to drop the tedium of maths and French as soon as possible. I just wish the government would stop pushing STEM to the exclusion of all other subjects and take a proper balanced look at what we expect our teenagers to do.