As for not being an essential service, I disagree, it is an essential service as making backups is essential, and there are still -way- too many people who don't make their own backups, so Microsoft doing it for them is not a bad thing.
Microsoft is ever so slowly adopting a Steve Jobs paradigm, that has potentially dramatic consequences.
And it's a decision on sovereignty Microsoft (and in fact also Apple) have no right to make without informed user consent and agreement.
"Users are so dumb the need to be helped" is the fruity cult approach that came from the iPod, which was only a music player, so one might argue that's ok. But now that the iPod has evolved into a digital prosthetic that manages all digital aspects of your life (and arguably the majority of all business and social ones), that's an overreach that wasn't anticipated, nor ever properly regulated or managed.
Data can quite simply get you into trouble and even killed. It's one of those lessons taught by the Holocaust to at least my generation of Germans and why we're so bent on data protection and data avoidance.
And Microsoft has proven again and again and again, that they are humans who automate mistakes. And then your data leaks or is being commandeered by someone Microsoft cannot or doesn't want to say no to.
Just to illustrate:
I have pictures of small naked children.
I really would like to keep them.
They are my own (the kids and the pictures), cherished mementos of them playing in the bathtub more than twenty years ago.
Now just imagine what happens once OneDrive decides ot replicate them after a patchday and does the content checking many governments want to make mandatory because of potential child abuse and pornography...
And if an AI could tell that they are my own, that would be even worse...