Gimp works really well, just that it is destructive editting.
As for the software not having features or not being useful, part of that comes down to: if a company offers a linux version make sure you use it. For a proprietary MCAD and PLM system from Siemens, we had a unix version, then windows, then when Linux was viable with support on SUSE and RHEL we had the exact software OEM aerospace and Automotive engineers used for design and management. Trouble is not enough companies used it to make supporting it a worthwhile effort, so they ditched the GUI desktop support. You can still run the few years old version. Maybe it will come back with Linux rising from 1-2% to 4.5% ; if that trend continues