In most top universities, teaching largely works through learning by doing. Its just that they keep the quality of assignments high. So your projects make up for it. Also note those taking online courses have an active interest to get good at things, so they would work on these projects.

In the real world you need as much as you can receive from a lecture. Beyond that mostly you have to learn on the job. So online learning will work for most cases. Yeah in some cases you can't fully learn it without a teacher, such cases will exist, but will be exceptions to the rule.

>>If someone said they were shutting down local schools and just telling the kids to watch YouTube and ask question online, I'd be horrified, the kids would get far less attention and teaching, and the kids would be far less educated. Also, few would have the self-motivation to pull it off.

There is a reason why despite all the awesome public education system US has compared to the rest of the world, only a fixed percentage of awesome people come out of it every month.

Every thing at the end comes down to personal motivation. You can't make anyone succeed without their participation and will.