

The question wasn’t “How long until you learned the language” but instead was “How long until you can watch an episode without subtitles”. I think there’s a huge difference there. Shows that are mostly action and lack a lot of exposition will mostly have simple dialog, and you don’t need to have a grasp on sentence structure or have a huge vocabulary when you can just recognize a few key words and get a general understanding.
I watched anime a lot in my youth and young adulthood, and found that after about 10 years of daily watching I could easily pick up a new show and understand the gist of what was going on. Complex words or exposition tripped me up, though. Nowadays I rarely watch anime but I’ve been studying Japanese daily on Duolingo for 4 years, and sometimes I’ll turn on a Japanese show as practice to try to recognize as many words as I can. It’s a totally different beast - Now I actually understand the nuances of sentence structure and have a much larger vocabulary, instead of just knowing a few key words. It’s a fun exercise.