How can I add different businesses to one account as the businesses in my area are filled with people who are not internet savvy and so they don't have email addresses.
What's the solution to this?

@Isreal
Business profile is linked to user profile and user profile require email. Hope this answers your question.

I understand that perfectly well. However, what happens to businesses with lots of branches across the country, will they have to create an account for each of their business profiles?

I believe there should be an option when one account can be used to add as many business listings as possible.

Can this be added in the next update?

No, 1 email == 1 business profile, such update would help just very few users.