Not counting monetization, the main difficulty with implementing true privacy - from the provider itself - of web services is the necessity to cut the "account

Not counting monetization, the main difficulty with implementing true privacy - from the provider itself - of web services is the necessity to cut the "account recovery" feature. When the provider can't access your data, if you lose your password, all of your data is gone forever. If you are willing to live with that, alternatives already exist, as others pointed out.