What determines the 'Owner' of a file/folder?

Hi,

I'm having trouble interpreting the info bar for a selected file/folder in a modern library.

Choosing "Manage Access" will show this for example:

Now, I can see that "Company Administrator" for example is "Owner" of that folder. I inferred that this is because he's a site collection administrator. In addition, "Stock Site Collection Owners" is a Ssecurity group with full control - also makes sense. However, why is "Hierarchy Managers" in here as "Owner"?

This security group does not have full control:

So this makes me wonder as to under which cirumstances a file/folder displays someone/something as "Owner".

Any ideas?

Thanks.