Hmm. For the first question I am not sure. There are a lot of educational resources out there that are free or low-cost, centralized or non-centralized. Families would worry less about cost and focus more on having their child put in effort in their studies. Khan Academy is one example that comes to mind. Various Youtube channels like patrickJMT helps too. Online resources can be used for homeschool purposes or as supplemental resources for school. Many of the learning websites (Udemy for eg) have that learn at your own pace feature. Teachers in public schools & private schools can also use online resources as an another tool for assigning homework, practice problems and administering online tests. Online learning resources in general do help students a lot with learning especially with technology.

In my area fees from grade school from grades 1 to 12 are not really a factor as it is tax funded. This is for public schools. Private schools do come with high tuition fees though. That is a bit of a separate issue. With other places I would not know the fees and whether or not school is expensive related to their wages & salaries in that region/country. At the university level tuition fees in USA & Canada are a bit high. More competition in post-secondary school industry could be helpful for reducing costs.

An issue I see is that if the alternative education platform centralized or decentralized would be recognized for jobs and the employment market. Learning stuff is nice and all but if the skills are not recognized then employment is not that easy. Some sort of accreditation or link to employers would be helpful. A decentralized solution in education could maybe work. I know of cases where programmers can get programming jobs in tech through self-study without a related comp-sci/programming degree.

For the widespread adoption question, I'd say more marketing and media exposure. Provide learning topics that are good alternatives to mainstream learning topics. (i.e Teaching about gold in financial literacy classes)

Hope this helps. Kind of writing stuff as things pop up in my head. I think I got a few more education post ideas from this.