.just a through z
It wasn't always thus. Britain adopted printing earlier and on a larger scale than most. When that happened, several letters disappeared for the sake of printers' ease.
Simple doesn`t always mean superior. Or
Indeed, though no European alphabet, including the Polish one, is especially difficult.
The same with pronunciation. Speakers of English freak out at the szcz sound (as in Szczebrzeszyn) however they're happy to say the word pushch