Playing it safe is putting it midly, its almost as if Chibnall is afraid to create compelling villains. After all, the Daleks are a cultural icon in their own right, those genocidal trash cans are arguably more recognisable across the world then the Tardis. So I think Krasko was made so weak because Chibnall was deathly afraid his 'cosmic rascist' would become charismatic even if the audience didn't agree with his views. Which is to the detriment of the story as a whole.
I get what you're saying but I think this attitude is the wrong approach. Rather then finding a weak villain to match the tone of this story what should've happened is finding a story to match the tone of Doctor Who. I've already seen plenty of comments online comparing Rosa to low sci-fi American shows like Timeless and I think that's true. Rosa has little in common with the rest of new Doctor Who, it's just missing that spark that made Doctor Who unique.