Re efficiency: 'ee' and 'oo' are efficient at conveying the pronunciation to the learner, in contrast to the discouraging, confused picture presented by the orthography of your own native tongue. 
Re modernity: you keep banging on about the fact that these spelling innovations owe their origin to the English Great Vowel Shift of about half a millenium ago. Who cares?! Surely you are like the oriental who fails to notice that our alphabet is more effective than his, and bangs on instead about an alleged 'debt to Rome'! I don't 'ignore that these spellings are typical for English,' it just doesn't concern me - they are also now typical for Manx!