This appears to be DOGE employees simply doing their job.
You may not agree with what they’re doing in a political sense, but if you were tasked with the same problem you’d come up with a nearly identical solution.
For example: “tenant admin” is probably the special role that can bypass access control (not audits!) and see and read all data.
This sounds scary but I regularly request this right from large government departments and I get it granted to me.
Its use is justified when normal access requests would be too complex / fiddly and error prone. Generally, in a large environment, there is no other way to guarantee 100% coverage because as an outsider you don’t even know what permissions to ask for if you can’t see anything due to a lack of permissions!
Seriously: sit down for a second and think about how you would go about getting access to make a full copy of an organisation’s data for an audit if you fully expect both passive resistance and even active efforts to hide the very things you’re looking for.