If the footage has left your premises and stored on someone else’s machine (the cloud), it’s now out your control. It could be accessed by an employee, accidentally deleted/tampered, or handed over to a government entity without your knowledge. This applies to any brand of security cameras as well as file storage providers and even VPNs

When motivated enough, governments can and do seize servers from data centers. A lot of the time companies rent them, so these vendors can’t even directly guarantee their physical safety