You might not know yet but WordPress is working on a project called Full Site Editing with the goal of allowing users to edit any part of their site in a single and coherent way using the block editor.
The project is based on a new kind of themes called “block-based themes”. If you want to learn more about the project and these themes, I’d encourage to check out the following links:
Full Site Editing and block-based themes are still very experimental, and since I’m actively working on the project, I decided that the best way to test the work we’re doing is to use a block-based theme on my own blog (the experiments is already successful as I’ve managed to discover some bugs).
I’ve now switched the theme of my site to use the TwentyNineteen theme being developed on the theme experiments repository.
I’m not going to lie, don’t do that unless you feel adventurous. The project is still heavily being iterated on. It is lacking a lot of fundamental blocks and UX interactions are not polished. That said, I was very pleased to be able to just open the Site Editor page and have a representation close to the frontend where I tweaked some parts of the footer/header without having to dive into several menus, widgets, customizer and some settings page. I look forward to being able to hide these pages entirely from my admin as I don’t need them anymore.