https://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot...

I count about 40 plus more which are not listed.

You surely could first make a dictionary or structure and fill it with these arguments. But then "kwargs" are just that, a dictionary.

I find the interface of the plot function pretty straightforward. There are a lot of options but it's pretty clear what they do and when to use them. Most often you use only some of them - but often different combinations. Splitting this up into multiple helper objects that need to be constructed and filled beforehand would turn the default one-liner into a ten-liner which is not better.

Maybe Ruby on Rails is an exception, but while I used to be a fan of default/keyword arguments, especially in combination, seeing how they were used there made me very much not like them any more. It's impossible to tell what's going on.

It's very clear there...

Similarly, in Swift, the order of defaulted arguments is significant. So you wouldn't see anyone do something like that crazy matplotlib method in Swift, because remembering the order of all the arguments in that function is impractical.