There have been many topics about sidebar customizing, for example:
- Sidebar customizability
- Ability to freely reorder Sidebar Sets and Favorites
- Customising Sidebar Layout
- Ability to customize Sidebar items
And Widgets and Sidebar / Dashboard updates#12 is on the roadmap for Q2 2023.
Also collections is on the roadmap for Q1 this year.
So if we can add collections and/or custom items to the sidebar then I believe we can do all you are asking in this feature request.