First, let’s differentiate. There’s education, and there’s training. Employers, mostly, are more interested in training, and I’d argue that it makes more sense to rely on institutions and pieces of paper when it comes to training, whereas for education they’re pretty much useless. I’d say education can take place more effectively in a library than a school, but not training. I’ll trust a self-trained philosopher, but not so much a self-trained nurse. Even vocational and licensing testing don’t work for nursing - you can’t test everything that can happen, so it makes far more sense to rely on trusted schools.