Contractors are often hired for budgetary reasons. It can be easier to get sign off to hire a resource for 6 months at $x per month than to hire a full time employee whose salary is seen as an ongoing cost, year on year.

6 month cost can be an easy sell. Lifetime employee can be more difficult.

I work as a contractor myself in Ireland, and it's usually large companies, consultancy companies or government agencies who hire contractors. It's rare (but not unheard of) for startups here to hire contractors.

Those 6 month contracts usually roll on, so effectively you're working as if you were a permanent employee, but on paper you're always only ever a 6 month expense.