All Japanese All The Time (AJATT) is well known in the Japanese language learning community. That's where the idea to sentence mine a fuck ton, put lots of words in anki and study, and immerse a ton in japanese media came from. Which later Massive Immersion Approach (MIA)/Refold would rebrand and sell as a product - the study plan amounts to make a lot of anki flashcards, and immerse a lot in japanese.
Khatzumoto's blog AJATT was the most extreme version of this advice, saying to listen to 10,000 hours and to do a lot of anki flashcards. His advice was intense, and yet it lead to a lot of people managing to learn Japanese - and hence why, ever since, the most common advice for studying Japanese you can find online has been "do these Common Words/Grammar/Kanji anki decks" and "immerse in Japanese media" (intensively or extensively). This is also where some polyglots first got the idea to study 10,000 words in sentence examples in anki, to learn a language - a plan that you can find many people on youtube mentioning.
I decided to peruse the AJATT blog today, see if it has any gems of wisdom I could apply to my own learning. 10,000 hours of listening is a LOT, more than most other sources recommend is needed (for example Dreaming Spanish and ALG would say only 1000-3000 hours is needed). 10,000 hours to master a hobby IS an often mentioned piece of advice though - like learning to draw, or write, or play guitar. So it comes from somewhere. 10,000 Hours: Building Listening Comprehension is a bit of a ridiculous article to read, but it makes a good point - you have more time in your day to fit in listening practice than you might realize. I love studying by listening, ever since I first tried audio sentence flashcards (japaneseaudiolessons.com, learner podcasts like JapanesePod101, my chinese listening experiment now), because I can fit so much more study time into my day. The article Why You Should Keep Listening Even if You Don't Understand is perhaps more ridiculous, as it goes against our assumption that listening to stuff you understand is what's beneficial. And definitely! listening to things you understand will help faster! That's why Dreaming Spanish estimates 1000-3000 hours of Comprehensible Input will make you B2 in a language. But who's to say 10,000 hours of input you understand sometimes but not always, couldn't also amount to the same benefit?
I am a big believer in "good enough" over perfection. And so I do think, if you are not listening very much at all, you are avoiding practicing listening, then deciding to listen to stuff you understand Some of is better than never listening at all. Basically, while I think AJATT advice to listen nonstop is wild and not realistic for most people... if you are studying (however you study) then chances are that SOME audio exists that you somewhat understand, so you might as well try to fit in some listening practice when you can. I am only partly listening for much of the time I'm doing my 'chinese listening experiment' because I can't fucking focus well, and I prefer to listen to stuff while working, exercising, driving, doing chores. It's clearly still helping me to listen as much as I'm listening, even with only partial attention on what I'm listening to.
(Not directly related, but for some wild study plans and activities people have come up with, explore the language learning community studying Japanese. The guy who planned to learn Chinese by 'just watching dramas' even if he didn't understand them, was originally a learner of Japanese, and has since gone back to studying Japanese).