Since then it's become clear that there are basically two categories of homeschoolers: those that want to bring in extra education beyond what the public school system can deliver, and those that want to bring in less education than the public system. Usually in the name of "protecting" them from some information for religious reasons. That's where all the attention and concern is. Because children can't advocate for themselves, especially against their parents.
(The UK had a recent scandal with illegal schools: https://www.theguardian.com/education/2019/apr/12/ofsted-unc... ; running a school for money - heck, even offering a childminding service for money - without registering with OFSTED is definitely illegal, while homeschooling is legal by default https://www.gov.uk/home-education )