Those numbers assume consistent effort — roughly two to three hours of focused practice per day. They also assume you are spending most of that time building things, not just watching videos.
The bottleneck nobody talks about
Most learners spend months watching tutorials, taking notes, and completing course quizzes. Then they sit down to build a real pipeline and realize they cannot. The tools are familiar but the skill is not there.
The reason is simple: watching someone else write code does not transfer the same way as writing it yourself, hitting an error, figuring out why it happened, and fixing it. That debugging loop is where the actual learning happens. Speed it up by building earlier than feels comfortable.
A practical learning sequence
This is roughly the order that gets people job-ready most efficiently: