I think the only real advantage of GIMP at this point is its age and stability. Gimp was around 20 years ago and it is more likely to be there 20 years from now than Krita. EDIT: my error - Krita is much older than I thought.
Moreover stability is important if you access it programmatically.
And yes, even that is not guaranteed by any means. It's just the area where Krita does not beat Gimp totally.
Krita was started in the previous millenium, too. I've been Krita's maintainer since 2004... If I have to think about what I did with my life, https://krita.org/en/about/krita-releases-overview/ comes to mind :-)
Just read this guy's vita. An entire long life of profit-oriented road rage, always using the law and presumably his connections to go after like everyone else for minor copyright and similar offenses, striving to make this planet a more miserable place for everyone else while raking in for himself. At almost 90 yo he finally got convicted for fraud and rather killed himself instead of going to jail. Not even his high-falutin name is all that real. At some point he tried to get courts deny people the right to even mention the fact that he was not born as a Von And Zu. Christ what an asshole.
Moreover stability is important if you access it programmatically.
And yes, even that is not guaranteed by any means. It's just the area where Krita does not beat Gimp totally.