jointplot doesn't warn for ax= argument in seaborn 11.2

[jhncls]

In seaborn 11.2, figure-level functions such as catplot, relplot, displot and pairplot issue a warning when an ax= parameter is passed:

UserWarning: catplot is a figure-level function and does not accept target axes. You may wish to try stripplot
  warnings.warn(msg, UserWarning)

jointplot doesn't issue such warning

import seaborn as sns
tips = sns.load_dataset('tips')
fig, axs = plt.subplots(1, 2)
sns.jointplot(data=tips, x='total_bill', y='tip', hue='day', ax=axs[0])

PS: Clustermap's message could be confusing (TypeError: heatmap() got multiple values for keyword argument 'ax').

[mwaskom]

I'm fine with this consistently warning, though I am curious about what one expects to happen here.

[jhncls]

A user who isn't very familiar with seaborn might expect that a jointplot behaves as an axes-level function, and that it can be combined with other subplots. So, just a warning jointplot is a figure-level function and does not accept target axes could point them in the right direction. (Related SO post: https://stackoverflow.com/questions/69286147/subplot-seaborn-white-box-failure )

[mwaskom]

I understand why the distinction between "figure-level" and "axes-level" is confusing for non-faceted {dis,rel,cat}plot, but isn't it obvious that a jointplot can't be plotting on a single axes, since there is more than one of them in the plot?

Unlike the plots built on a FacetGrid, there's no axes-level correspondent to direct users towards here.