First of all, most Japanese people don't know English. In fact, their level of English, in my opinion, is probably one of the worst in the developed/developing world... They can't produce English at all. They can perhaps read and understand certain things but their speaking level is next to non-existent.
Secondly, Japanese (and languages in general) are highly employable. At university, I did French, Spanish and Japanese. After graduating, I did some freelance interpreting in Japan while working at a private firm assisting medical and business clients with English translation. I'm actually thinking about applying for the diplomatic service and CIR JET position (
http://jetprogramme.org/en/positions/) this year.
My friends who did a Japanese degree have gone onto the following jobs: working in immigration offices in Japan, working in local Japanese governments such as Fukushima, Beppu and Kyoto as the Coordinator for International Relations (one such example:
https://rediscoverfukushima.com/), working at the consulate general (embassy) in Edinburgh, working for the NHK (Japan's version of BBC) in both Tokyo and London, investment banking, working in Japanese translation (environmental and video games), practicing Law in Japan, working at a local sake brewery in Okayama (
https://www.originsake.com/?fbclid=I...0neClapyuUuqyY), lecturing at universities in Japan and the UK and so on and so forth.
My university friends who studied French and Spanish have gone onto working at the European Parliament, investment banking, tourism and so on.
When you study a languages degree, you don't just study the language. For example, during my undergraduate degree I took various modules on Japan-China foreign policy, international relations, politics, Japanese society, classical literature, modern Chinese and Japanese history from 1600s to the current day, French immigration laws, Spanish journalism writing etc. What's more, regarding the language component of our degrees, there were modules consisting of translations of dense political documents, medical documents, historical religious documents, both classical and contemporary literary texts as well as journalistic articles among many others.
Thirdly, if you're wanting to learn Japanese, I
highly recommend getting some good textbooks and not relying on sub-par websites or apps. You really need something of high quaoity to guide you when you first learn a foreign language like Japanese and I'm afraid that most of the free resources won't cut it (if you're serious about learning the language to a good level). These are the ones that I personally recommend:
Genki 1 -> Genki 2 -> Integrated Approach to Intermediate Japanese -> Tobira: Gateway to Advanced Japanese
I used these textbooks when I first started Japanese at university and they explain grammar extremely well and introduce hundreds of key vocabulary. I can't recommend these enough because they're absolutely fantastic. You could work through each textbook by doing an hour a night or something and it wouldn't even feel like 'work' as the textbooks are well written and allow you to enjoy learning Japanese.
Even though the first 3 above textbooks were originally made for classroom use, they're still excellent for self-studying Japanese. There are also additional Genki 1 and 2 kanji and workbook books that you could buy to supplement the main textbooks and get some extra practice in but they're not essential.