Maybe so, but I hadn’t perceived this thread as being focused on the specific question that you have articulated above.
If one has so many “favorite” items that a search is required, it can be argued that these items are not really “favorites” in any meaningful sense of the term.
I think that you’ve maybe put your finger on one big issue with the new design. An ideal browser extension should be optimized to minimize the need for scrolling first, and to minimize the need for mouse-clicks, second. Therefore, the decision to put many disparate functions on the same browser extension page (the unified Vault page) necessarily increases the amount of scrolling and clicking required. Having many tabs will make more efficient use of space (requiring less scrolling), while requiring only a single click on a navigation bar (furthermore, in some cases — like searching — the browser extension could automatically switch to the relevant view).
Unfortunately, the navigation bar in the browser extension is severely hamstrung by being constrained to look like the mobile app navbar (which is designed for navigation by thumb, something that is completely irrelevant to the browser extension). As demonstrated by @nematode in 2021, it is possible to comfortably fit around 8 navigation icons in a navigation bar optimized for use with a mouse. Therefore, there was no need to reduce the number of navigation icons from 5 to 4.