The short answer is no, you do not have to. If you use another service to host your site, we cannot force you to switch. But be aware that if your website has any issues that would have been prevented with managed WordPress hosting, it will be your responsibility to either resolve the matter on your own (which includes calling and coordinating with your web host’s customer service) or to pay us to do so (at an hourly billable rate of $90 per hour).