Choosing a degree program with 'low academic standards' I am not sure if this is the right StackExchange to post this kind of question. If not, I apologize.

I currently have a problem in choosing a undergraduate program to study. I am mainly interested in software engineering, life sciences and mathematics. As a result of this, I have bought multiple undergraduate text books for these subjects to teach myself all basics of these fields. This includes things like programming, theoretical computer science, data structures, algorithms, ... , set theory, linear algebra, real analysis in one and several variables, complex analysis, abstract algebra, ... , zoology, chemistry for biologists, genetics and so on.

Now, when I look at those many different degrees available, I am kinda stumbled. Because all degrees have kind of 'nothing to offer', as I see it. By this I mean that I feel like I already know 66% of the course's content, especially in mathematics. Of course, such programs can offer more things like help from tutors (which kinda became irrelevant due to the internet), field works, expensive laboratory experiments and so on. But I don't think that programs like for mathematics or software engineering have much of such things. And I am not sure if I really want to pay 9000£ a year for such a degree then. So a degree in biology would be the best.

But then again, I am just afraid of taking a biology degree, because I fear people (both in industry and academia) will deny me because this particular degree I have pursued did not include a programming course or fundamental mathematics, even though I did teach such things myself.

Now I have no experience in how people might react when I write in a CV things like 'I might have a degree in biology and not your desired degree in computer science or mathematics, but I do think that I fit your job as statistician very well, because I taught myself modern mathematics, methods of statistics and programming. (even though I do not have a certificate proving any of the listed skills, just believe me.)' 



Edit 1 'To the Dunning-Kruger effect':

Well, you can often view course structures and syllabus' for the courses included in your degree online. Let's take for instance the Bsc Mathematics (G100) program from the Imperial College. Under 'Structure' you can read what you'll learn in during this degree and you can even see all the syllabus' for all individual courses, such as for 'Mathematical Methods I'. When you now have different books covering the topics listed plus other sources from the internet (like videos, papers, articles), I do think that you can teach yourself a lot of the degree. You even have people on StackExchange you could ask for help. Despite all of that there is even a list 'Appropriate books' in which the Imperial College recommends you books to read for that course!
Since the sentiments already appear in your question, let me make this extremely clear:

Modern university degree programs serve at least two distinct purposes: education and certification

I entirely agree with you that a if you already know the material, for the education purpose of the degree it seems redundant to take a course on a subject you have already mastered. But as you have already indicated in your question, employers, graduate schools, and other agencies may choose to use your university transcript as evidence of said mastery. (Though, in some fields, the professional society provides their own certification function. For example, the society of actuaries have their own pathway toward membership. Those fields may be more "friendly" to someone without a formal degree.)

But I do wonder how you came to the assessment that you already know most of the material in offer for the degree programs. The Dunning-Kruger effect is a well-documented phenomenon in which practitioners of low expertise tend to overestimate their competency. While I am not saying that this necessarily apply to you, frequently in a classroom scenario one of the most difficult things is to first break down the students' existing misconceptions before actually teaching the material. 

That said:

From your post I gather you are based in Britain. One option for you is to pursue a degree outside the United Kingdom. The liberal arts type education in the United States, for example, give greater flexibility in the choice of coursework toward a degree program, and frequently you can make special placement arrangements to participate in higher/graduate level coursework in lieu of the introductory courses. Additionally, given you interest, maybe you should investigate degree programs in mathematical biology. Modern math bio tend to combine theoretical and computational mathematics (which involve a good deal of programming and simulations) with life sciences.