If you’re learning on your own, you get to pick and choose what you want to learn. That almost always means you’re going to choose not to learn something that is actually important. Having a good teacher and a structured education system means there is an expert who will make sure you learn everything you need to know and you haven’t missed anything.

I often read through books and spend time learning materials that I’m not super interested in. Not because I like it, but because I understand some topics are just essential to understand.

Don’t need a teach for that instruction though.

the point isn't that you understand there are topics that are essential, it's to have someone to identify what is essential.

we all have blindspots, much more when we're just starting something new.

> it's to have someone to identify what is essential.

You don't need "a good teacher and a structured education system" to identify that, because what's essential in a domain is not a function of you. It's a function on the domain itself. Or, in other words, it's enough for a good teacher somewhere to identify important areas and create some structure, and everyone can benefit. You don't need that teacher for yourself (but you might want to read his book).

Or, you can notice such experts exist and share their opinion on what is important to learn, and use that opinion to guide your learning.

That's called having a teacher.

What I meant is that instead of having a teacher - a person you interact with, and who is at least aware of your existence and learning goals - you find existing material published by experts and use that to guide your learning - without ever having to be in contact with them.

What about feedback ? Isn't it an important shortcut ?

Some kind of feedback is required. If you can get personal feedback, from 1:1 interactions with a teacher, all power to you. But many people can't, and have to seek out feedback on case-by-case basis (e.g. by sharing their work on-line), and/or from non-living sources (e.g. your solution working is a form of feedback in itself, quite fertile if you pay attention to it).

Compared to learning from an expert tutor/mentor 1-on-1, or even getting expert advice about where to find resources, it is (a) pretty inefficient, and (b) tends to leave gaps in basic knowledge.