The Wall Street Journal has a Pros/cons article on this question … which is at the core of Social Impact of Technology in Education.
My son-in-law teaches a university class where students get the “lecture” portion online, and come into class to work on projects/homework. My granddaughter has online assignments regularly, many key tests are done online, and they don’t get ‘snow days’ — in case of inclimate weather they stay home and login. Programs like the Kahn Academy, and a number of Universities offer courses free to “audit”.
At the same time, kids need the real world collaboration, social experience, ideally no bullying, and ideally sufficiently strong (positive) peer groups that help them develop a bunch of skills that are real world based.
What are the key references you find informative on the question of how we educate the next generation?