Why do lots of japanese words have so many vowels?

I noticed lots of words follow a consonant, vowel, consonant, vowel, etc. structure. Why is that?

I'm a primarily English speaker so for the few words I know it seemed like almost every word follows that pattern or close to it. Even the words that are an exception to the structure are only a letter or two off.

Example of repeating structure: Osaka, Kawasaki, Pomodoro, Sumimasen, Sayonara

Example of structure exception: Konnichiwa, Hashimoto, Arigatou, Tomodachi