This is an old debate. Is it better to focus early on a specialization or to provide a "well-rounded" person with a broader but less deep understanding? In either case, university education is not the end of learning, so which is most helpful for the future?
I remember in my 20s visiting the UK from the US and talking with other researchers there my age. I was surprised that I knew more about European history than actual Europeans. This is solely due to taking a European history course my last year of high school, while they specialized early in science.
I took a course in psychology, and college one in sociology. These have helped inform my understanding of group dynamics in software project teams.
If you believe that people can and even should change careers in their life, then a diverse education may make more sense. (In the US parlance, "reinventing yourself.") If you think people should stay in the same field, then focused, specialized training may make more sense.
Personally, I prefer a diversified education more than a focused one, but as someone raised in the US system, that's perhaps to be expected.
Finally, and only to highlight the humorousness, it's "A levels" instead of "A leves" and "you" instead of "your." A STEM course of course doesn't focus as much on writing as, say, a history or literature course. ;)
What I know about you is only what you have written. In my experience, most people who misspell are not dyslexic, so no, I was not dissing you because of your dyslexia.
I know nothing about your country's internal politics and cannot comment about the last. I was talking about 'school as prep for Uni works better.' It appears that you want a different discussion than what I can provide.
If you have A leves in Maths and the sciences your probably have worked out if you want to do a STEM degree.