Fedora still provide Gimp 2.8 as a standard package
Not a bug, but an open question on the way major software are delivered on Linux users.
Despite Gimp 2.10 is a noticeable step further, like the great improvement of the brush size widget, Fedora 28 still provides Gimp 2.8 as a standard package.
Users have to install the modular package to get 2.10. In comparison Firefox is regularly updated to the last version.
Is there serious reasons to do that ? Is Firefox team more active ? etc.
My point is that on Windows, users are free to install the software. On Linux, we are more dependent to the package maintainers which sometimes lag a while ... or maybe distro packages are just useless ...