This is great but, why wouldn't a business owner do this for themselves?
They can but:
They may not know about it
Very difficult to meet the qualifications and do the paperwork- unless you have HomeZon
No online reputation (RepZon!)
People are happy to pay others to simplify things for themselves
Technical abilities- you may be good at installing light fixtures, but using a computer is not your forte.
There are countless services that business owners theoretically can do themselves but opt not to. For example, marketing agencies routinely charge to set-up Google My Business accounts despite it being simple and free. They also require businesses to send them a PIN they get by text/email/mail - yet this does not prevent business owners from opting to pay others to take care of this for them. Service providers have a business- anything that can increase revenues with little effort on their part, they are often happy to pay for.