I agree, but to me it is extremely hard to decompress. I've tried many times to get familiar with staff notation but I never could get an intuition of how it works.

Sure. I remember when learning to play the piano as a kid that it took sometimes seconds to decrypt the next key when learning a new piece.

I've understood that for a large category of adult learners, when starting on an instrument for the first time in their life, it's the staff notation that creates an usurmountable barrier. So, yeah, it's not definetly 'easy' for most beginners.