I’m working with subtitles files or kindle books (which i turned into HTML so I can use yomichan) so almost zero data entry since it’s always just copy-paste.
Add to that the dictionaries I’m using are in-built into anki and only require a single click to transfer definitions on to the card, and that native audio and furigana can be added with one button, it really doesn’t take much time to make 10-15 cards per day.
oh yeah I also used subs2srs to pre-make cards so I can pick the cards I want in the beginning although I’ve moved away from this a bit at this stage.
Really the card making process only takes around 10mins per day (less if they are pre-made using subs2srs).
And 10-15K will take me over 3 years anyways lol.
As for graded readers I don’t see the point of them especially if you have knowledge of kanji. I went from reading subtitles on anime and Netflix drama straight to light novels (キノの旅 to be specific). I should note that I was around 500 hours of immersion at that point.
I feel graded readers are for Japanese kids who are still learning kanji, since their main benefit is that they are graded per school grade. I tried one many months ago but found out they still have the same number of unknown vocab as a regular light novel or manga.
Plus they are more expensive than novels. Light novels are anywhere from 300-1000 yen on Amazon from what I can see.
edit: I should add that during the monolingual transition phase, which I’m in right now, it does take quite a bit of time to make cards since you are digging through definitions, trying to find sentences, etc etc (the core10K deck that people mentioned here has actually been quite helpful for this). But hopefully this phase will only last a few months.