Great point on what would happen to mass-produced items like laptops if everyone moved to remote cabins in the woods to live cheaply.

And yes, a drawback to educating yourself via videos or reading (or even by taking some tests) is that it is relatively passive. A hands-on aspect is essential to a lot of skills, like learning to write by writing, learning to use machine tools by machining, learning to do chemistry by mixing chemicals, and learning to use a language by speaking it in important contexts. And setting up such contexts is one value of good educational settings (either in or out of schools).

As a parent who home-schooled from K-12, definitely the lack of easy access to some settings where various skills could be practiced was a limitation. We tried to make up for it as best we could in other ways.

Some learning can happen virtually to an extent, like virtual chemistry sets (even as they don't convey the visceral feel of working with glassware and liquids and such).

I'll be curious how using ChatGPT to learn languages works out:
https://www.howtogeek.com/chatgpt-conversational-mode-to-pra...

There is also an project at RPI for people to learn Chinese in a virtual Chinese setting with characters who speak Chinese:
https://research.rpi.edu/about/signature-research-thrusts/me...
"Students learn to speak Chinese through the Mandarin Project’s virtual reality, synthetic intelligent characters and gamification."

It is also harder to learn a language when the people you are talking to want to learn or practice yours and so are motivated to speak your language to you. So as a consolation prize, maybe you have helped some Berliners become better English speakers? :-)

Age may also have to do something with language learning -- but not as people expect. When people are young, they are often less embarrassed by making mistakes, and are full of enthusiasm for something new, and they way they are taught is usually point and name and speak and question. Adults tend to try to avoid mistakes, may have other more interesting or important things to do, and also may end up in boring textual drill-and-practice rote learning situations. Those are some of the reasons it is harder to learn languages (especially a first foreign language) as an adult.

A related funny XKCD on simulation and learning (where Kerbal Space Program makes a seemingly difficult learning challenge fun when done in private and also has no significant consequences for mistakes so you can play around with ideas like a kid again):
"Orbital Mechanics"
https://xkcd.com/1356/

Some people are just also better than others at languages for whatever reasons.

Also, sometimes immersion in a context for a length of time just makes the difference. One of my German teachers in High School talked about studying abroad in Germany when younger and speaking only German where they were, and they said they felt a real turning point was when they had their first dream in German. I'm guessing maybe you must be in a situation where you can still speak English or whatever your native language is at work and at home, and so speaking German just is not that important to your daily life?

Anyway, wishing you some dreams "auf Deutsch" if you want them. :-)