Yes, older texts omitted the ʻokina in most situations. Including the ʻokina and kahakō in written text is a recent innovation, and is particularly helpful when starting to learn the language. As your vocabulary grows, you will find that you know how words are pronounced without the markings, and that, through context, you can differentiate words that are spelled the same but pronounced differently and mean different things. In my opinion, it is faster to write without the ʻokina and kahakō. I use the ʻokina only to differentiate between koʻu/kaʻu/oʻu/aʻu (first person singular possessive pronouns) and kou/kāu/ou/āu (second person singular possessive pronouns).
I nui ke aho a moe i ke kai, no ke kai kā hoʻi ua ʻāina.