As a software engineer, basically all the skills I use to do my job on a day to day basis are …

I would think that software engineering is the exception that proves the rule: people with domain knowledge are highly motivated to share what they know, ask questions, consolidate knowledge, and refine processes using the Internet. Working in another field (public services might be a good example) it’s often not possible to test out hypothetical solutions, or find relevant expertise, or to even discover that whole areas of knowledge actually exist. In that context, relevant qualifications have a little more weight.

To be fair, technical skills training in the UK is currently mostly delivered through apprenticeships. The model is 80% "on the job", 20% "off the job" training. So, in theory at least, they should deliver the kind of experience and informal mentorship you're talking about, alongside classroom based training (which is supposed to cover fundamentals, theory, etc.). In practice, how well this works depends on how effectively employer and training provider coordinate, and how committed the employer is to delivering on the mentorship part.

For me it's about being given dedicated time and space to actually upskill - sure in house training is (the most?) important, but what about developing new skills that no one in your company already has? Reading blog posts is all well and good as a software engineer but for many roles this is not an option as there might not be high quality content publicly available online.

Economists have a habit of abusing data. It's seen as preferable to simplify the system enough to test a hypothesis than to acknowledge that the system is too complex to analyze. A little too much physics influence and not enough engineering.

very much this. i am applying for a workvisa, and they ask me for my degree (which i don't have) because it counts more than the decade+ of work experience running my own business.