I run multiple linux computers and servers, and keep ext formatted usb drives to transfer files between them. Today I learned that Android doesn't support the ext linux filesystem. As I understand it, it is entirely up to the oem (Samsung) to enable this support in the kernel. ExFat is just too limited for my use cases, as it doesn't support large files etc.
While this may have been done for simplicity (only showing a format button and no options), this is a power user device and should at the bare minimum support reading and writing to the drives, even if formatting isn't allowed. Though adding a simple more options button in the format dialog would never hurt anyone. Even apple has support for HFS+ and APFS on their devices. It's a silly limitation that makes Samsung's "pro" level devices just that bit less useable.
TL;DR Ext support should added because apple supports HFS and APFS
