Why is learning programming such a long process??

Answer 1

It is the same as if you learn a craft. In a couple of days you can perhaps learn to hammer nails into a board, but if you want to build a cabinet, a chair or a table it will need more time.

Answer 2

Because programming is similar to any other skill, all about practice and getting experience:
Not only learning programming languages but to think as a programmer and to write codes in the best way possible