Many Letters are Dispensable
Many letters do not contribute much to the readability of a text. They can be omitted without making the text illegible.
This applies especially to the vowels. Or the letters N and S. Actually, they are completely superfluent.
Just try it out aon this page.
Pangrams
A pangram is a sentence using every letter of the alphabet. It makes the effect of the redundancy reduction clear.
The five boxing wizards jump quickly.
Five quacking Zephyrs jolt my wax bed.
The quick brown fox jumps over the lazy dog.
Heavy boxes perform quick waltzes and jigs.
A quick movement of the enemy will jeopardize six gunboats.