Hiring a WordPress website design company is your best bet, especially if you find yourself working in the conditions below:
You don't have time to learn a new skill or you don't have to time to maintain another ongoing project
You want a highly-customized website with customized themes, menus, and content
You have a budget that allows you to hire a WordPress development agency
You have complicated, specific, and unique project requirements
All of these situations should lead you to hire a WordPress web design agency instead of doing the job on your own.