For a non IT experienced user, creating a partition with the Partition Manager GUI is relatively easy. The hard part is if the created partitions do not have read and write permission. It is not possible to set the permission using familiar Dolphin GUI on the resulting partition. There a long series of command line hacks and special knowledge is required. 

Use case: create an EXT4 partition on an internal SSD on Kubuntu 20.10. Then attempt to copy files to it. 

See the Gnome Disks application can create a partition with user permissions already set. 

This is a showstopper for normal users who cannot use the partition they just created. Any easy solution would be acceptable.