I mean why is outlook even centralised? If a company has 600,000 employees, why don’t they get their own infrastructure? Why is it all dependent on central Microslop infrastructure in America

Because microsoft sort of pushes you into it.

Because there’s more to Microsoft 365 than email and there are no good solutions for the non-email parts.

It's on days like this that Microsoft could really learn a thing or two from Google's SRE culture. These large tech companies have far too many internal dependencies, creating massive blast radii when something goes wrong.

It's a pain to administer.

That is exactly the question that needs asking and answering.