Storage of User Files

Trying to figure out the best option for storing department data files. For most of our departments, we are using SharePoint Online; however I have one department that shares Adobe files; PSD, PDF, and AI files. These files can be quite large and over a year, take up as much as a 1TB of space.  SPO, does not seem to be the best option for this.  I want something that can be easily accessible for both Windows and Mac clients.  I was thinking Azure Storage more so Azure File Storage since the last time I check, it was not easy to give access to a blob.  Some of the files would eventually moved to cold storage which makes cool or even Archive storage a possibility but again, needs to be access to the end user.   Can any one assist on the best options. Thanks.