They are baffling and ridiculous but they are consistent in that. Once you learn one baffling and ridiculous rule, you can successfully apply that rule to correctly pronounce almost any new word you’ve never encountered before. Eaux is a stupid fucking way of writing “o” to be sure, but at least you will always immediately know how to pronounce it without ever having to guess, or hear it from someone else. Meanwhile in English you write “read” but you pronounce it “read”.
There are of course exceptions, but show me one language in the world that has none.