I am not too sure about accessibility of all subjects. More esoteric information is still locked away deep in forums, youtube videos, or maybe paid online classes. For example a few years back I quit my job and spent two years slogging through trying to learn ruby and ruby on rails. There are countless tutorials and videos detailing how to get simple stuff going but more advanced stuff seemed to only be available if you end up in a Rails shop and learn hands on with experienced developers. All the interviews would catch me off guard asking about more intermediate ways of writing code in the "Ruby way". As someone who wrote Java, if the logic seems right to me, how would I know if I am doing it the "ruby way"? Same goes for Rails(things like active support are not covered by many learning locations).

This also bit me yesterday in a completely different fashion. I was attempting to replace the battery of an iPod Nano 3rd generation. This device is notorious for being very fragile to disassemble and repair. I managed to solder in the battery connectors only to start seeing the board heat up immensely. In removing the wires I burned one of the vias. Now I spent hours looking for a schematic or some info explaining what each via was for. I had to resort to looking up various youtube videos and asking on discord...no dice.

There is something special of having a structured curriculum that is trialed and tested so that you can go from a to b. I don't know if Khan Academy is that but local school curricula may be still relevant because of this.