The thing you're laughing at is how you deal with coffee grinders that spit out clumpy coffee. If you don't break the clumps, the high pressure water from an espresso machine will distribute unevenly throughout the puck (choosing to go through the path of least resistance) and will be the difference between drinking a notoriously-finnicky-to-get-right light roast and battery acid.

It's just physics, and something you can check for yourself in 5 minutes or by asking any chemical/food engineer who knows the basics of extraction.