Yea I don’t think that is really accurate if you wanna get to a high level. It takes a lot longer than that. I did 1500 hours of dreaming Spanish and while I know a lot of Spanish I’m not where I thought I would be. It would probably take double that to reach a high level.
Here’s a good video about a woman learning German through comprehensible input. She claims she didn’t do much read mostly listening and anki. https://youtu.be/fgx090oikks?si=2_f2JAcYU1L8Qw5m