Some of the side menus are far too long and crowded. In January, we added a setting to prevent them getting even longer and more crowded: python/cpython#114318.
I think tables at the top can be useful, especially if in many cases you want to find a thing, and when done, can close the page. No need to navigate back to the top again. See the built-in functions for one example. It would be good if Sphinx could generate them rather than manually building them.
I think it’s worth looking into separate pages per method, or at least breaking some of the huge pages into more manageable chunks. Some of our pages are huge, which are hard to navigate and bad for SEO.
Another idea is to change the theme. At the core sprint, I made a quick demo using the PyData Sphinx Theme, as used by projects such NumPy. This is a quick demo, the header and footer and other custom stuff would need adjusting, but a big benefit is there’s a less cluttered left-hand menu, and it also adds a right-hand menu. We’d also benefit from the huge amount of work being put into the theme, including lots of accessibility work.