Content Creation Strategy

Let's say we are going to prepare an article titled "Hairstyles". In word research;

Hairstyles for 20 years old

Hairstyles for 30 years old

Hairstyles for 40 years old

Hairstyles for 50 years old

Hairstyles for 60 years old

In this way, we have subheadings. What is the most logical way to plan content in terms of SEO here?

Should all headings be included in a single article or should separate topics be opened for each subheading and linked to each other? Does Google want a user to find what they are looking for on the page or navigate the site?

If they are all going to be one article, is it reasonable to include the word Hairstyles in each sub-title? What way do you think should be followed?