Are we hoping ax.set will be canonical? I agree these have a lot of manual fiddling, but I don't usually do that much manual fiddling, and therefore ax.set is usually more effort than its worth...

Are we hoping ax.set will be canonical?

That's a conversation to have (and depends on the meaning of "canoncial").

IMHO:

• ax.set cannot replace all ax.set_* methods because it can only handle one parameter and some of the setters have more optional ones.
• ax.set should be regarded as a shortcut. It's easier to read and less to type compared to all the boilerplate ax.set_.
• Originally, I'd been skeptical on ax.set (i) because it's redundant (ii) because it's not discoverable. For (i) I have now the position, that readability tops "there should only be one way" in this case. (ii) should become better with Better document Axes.set() #19884.