Support editorconfig out of the box
IMHO gedit should support editorconfig.
In GNOME Builder e.g., this is included by default. See https://editorconfig.org/#download
Oh, just found out I've already reported it, but the bug is still stuck in the old Bugzilla ticket tracker, so let's see this issue as migrated. It even was in 2016 that this issue has been reported there.
I've also written in the forums about it.