Active Directory – The cheapest way to set up a domain controller with AD-DS for a small business with multiple locations

I work for a small company with little IT infrastructure. We want to be able to associate all the computers in the same domain to apply group policies and other management functions. However, we have 15 offices with 1 to 2 employees per office and 10 in the company with a total of 36 employees. . For me, it makes no sense to invest in the infrastructure to configure a domain controller with a firewall at each location.

Based on my research, it would seem that moving everything to the cloud (Azure) or taking a hybrid approach with our on-premise server would make more sense. Is my thought correct here? Is there a cheaper way?