Most of our customers use Edge, Chrome, Firefox, and other popular browsers. The requirement for the SVM console is only for certain functionality in the admin console; specifically managing WSUS and creating/publishing patches. The new patch automation process does not require ActiveX, but individual patch creation does.
The SVM console simply does things browsers are not normally authorized to do. It talks directly to WSUS, it writes to the file system to create patches, etc. The need for ActiveX (and therefore Internet Explorer) is not a matter of browser support as much as a dependency to do things security otherwise restricts.
Please have a look at the detailed blog explaining why we need IE for SVM patching capabilities.