Well, how much do you save?
I can see this in your plans:
Administrator Console access (Analytics, control, data protection)
Selfhosting everything and then relying on a service/application requiring an account in the “cloud” that does “analytics” and whatnot is just defeating the purpose. Although it would make a difference if you have a Nextcloud server app that does all of this so it would be still contained on a selfhosted system. 
There are other client apps for multi-cloud sync that do not require an account linked to “somebody else computer” (just another term for “cloud”) uploading potentially sensitive data, except for maybe a mail address for license registration.