A core counter argument to their base premise is that learning effectively is done in person, as part of a social group, in a physical space dedicated to learning, with hands on practice. It certainly seems to be the core takeaways of Waldorf/Montessori/constructionist/etc. approaches.
> When our kids were in school and struggled with a class/teacher/subject, we would get them a tutor to come to our home in the evenings.
In other words, there's a reason they paid the tutor to come in person, and not tutor over Skype or the phone.
The author speaks of their intent being to open up access to education, and replace the "outdated tech" of physical schools and classrooms. I need to be convinced that successful execution of this plan (and its inevitable percolation into policy if it makes financial sense - which I have no doubt it does, for a VC to take interest in it) won't result in a two tiered system, with students from poorer families getting free, public education over video lessons, and students from wealthier family being able to attend private, more expensive, in person schooling.