Even here in the UK, taking a GDL and LPC/BCPL is a very expensive proposition. There are no real free resources, if you want even a sniff of it you are putting down serious cash. I know because I looked very hard at doing it, and opted out partly because of the perilous costs involved.
The engineering example is very different: helping high school kids take nurture an interest in engineering is definitely a common volunteering trope. I'm not sure it's the same as giving potential practitioners free professional training.
> I think your perception of what other professions do might be limited by your own experience, though.
Politely, I do not think you should be making that assumption about strangers on the internet.
In the legal space there is a ton of free information and resources out there, and plenty of ways to work personally or professionally with the law that don't require a JD. For example part of my job is to advise colleagues on contracts and IP issues. I have no formal legal training; I learned on my own and have built up trust in my ability based on demonstrated competency. Not that I'm some special flower; I know other people with similar responsibilities.
Of course we also have actual lawyers on staff, and I'll never be able transfer to that role without shelling out some $$ because it is a formally defined credential. By definition there's only one way to become a lawyer.
Conversely, the lack of formal credentialing in software development makes it hard to evaluate the quality of the "professional training" that is available for free. If I go through the COD3 curriculum linked up top, what job can I reasonably expect to get? I don't think COD3 is comparable to a 3-year post-graduate degree in law.
The free-for-all that allows for open-ended innovation also allows a lot of open-ended promises about the value of free things. And because they're free, there's not really any accountability if the promises fall short. I don't think this is a bad thing; but it does make it hard to cleanly compare it to more formally credentialed industries.
I think your perception of what other professions do might be limited by your own experience, though. Just to go in order:
Legal: My aunt is a lawyer and volunteered her time in a legal "clinic" where people with landlord/tenant issues could come in and get advice for free. She also worked some of her professional time on cases where the clients did not have to pay, a practice that is common in the legal industry, called "pro bono."
Engineering: There are a wide variety of student and volunteer activities that are well-supported by professional engineers on a volunteer basis. For example one of my coworkers volunteers his time evenings and weekends to help "coach" a high school robotics team. And you may have heard of various other engineering challenges like popsicle stick bridges or egg drop competitions.
Medical: Several friends have transitioned into working in the medical field through free opportunities, primarily by volunteering with local rescue squads and first responder teams. These teams are typically supported/led by some folks with professional medical training, but anyone can show up, volunteer their time, and get medical training.
Ultimately, to work in these fields professionally, folks need to get a credential of some kind, and that might cost money. That's not true of a lot of software development right now.
But I think that is primarily because computing is such a young industry right now. All industries start out that way. There were times in history when you did not need a credential to work with the law, or to design machines, or to treat illness.
But as these professions had a larger and larger impact on society, society imposed higher and higher expectations on practitioners... expectations which required more formal structures to satisfy.
I predict the same thing will happen to computing technology, at least at the high end. It's already true in some areas like life-critical embedded systems. You're not going to get a job writing code controlling the ISS after doing some free online tutorials.