Not just the privacy aspect should be looked at, many companies are basivally vendor locked and Microsoft has just recently announced price hikes that you can’t get around and avoid.

My experience is that usually overall it’s more complex to self host but also cheaper. Yes you hire additional staff for managing said services and ypu have to get the knowledge to your corp. But in the long term it just pays. Plus since administrating these cloud solution seems to get more complicated rather than easy you’d have to hire regardless.

But now costs are controllable and the biggest plus is that you don’t have to use a common solution for your individual demand that never meets exactly what you need.