As someone who recently tried to use Blender for an extremely simple task... Blender's UI is absolutely terrible and should not be used as an example of anything except how to design an unintuitive UI.
Regarding Blender specifically:
Do you have a background in 3D modeling?
I am genuinely curious.
I don't come from an digital art background and I bounced off Blenders UI several times but after doing a tutorial or two now I find I can use it for simple things. I have always wondered how much it was 3D modeling in general vs. Blender specifically.
In a similar case I have used both Inkscape and Illustrator as an amateur and, much as I love open source, there is no comparison. Illustrator was significantly easier to use and worked better.