The short answer is no; you don't have to connect your Google My Business account within this section of the on-boarding setup.
If you don't want to then you just need to click the button 'Skip this step', as highlighted below:
This section is primarily for businesses who operate within a specific are/region, for example a plumber who operates only within their local city. This is called local SEO.
If you serve customers nationally or internationally then this section is not as important.