@Davis-Cook , I hope all is well. The short answer is that while there are benefits you get from Domain Joining, you would have to be prepared to leverage them in order for the additional work to make sense.
When you say you are not using Azure services yet, you can join machines to a domain that is EITHER on-premises or Azure based, but the value of doing so is in the enhanced management and services capabilities that would unlock for the organization.
If you are wondering about the specifics and the value propositions, check out the following:
https://docs.microsoft.com/en-us/azure/active-directory/devices/concept-azure-ad-join
The use of MDM via Intune would be the key thing to think about for you, as that would give you policy-based control over the endpoints for instance, especially the Kiosk machines.
If you have more questions, please let us know.
Good Luck !!!
Cheers,
Adam