"The magazine had a little travel article, and it was written in English on one page and Thai on the other." Interesting Sunday study but language is supposed

"The magazine had a little travel article, and it was written in English on one page and Thai on the other." Interesting Sunday study but language is supposed to be spoken. Arab and Hebrew skip vowels in written texts so they seem to be more efficient. But filling in these vowels requires cognitive extra work. That's why both languages offer extra notation for people who aren't that experienced with the written form. Does it make a difference when speaking a language?